For three days, she was simply an unidentified female body, cruelly decapitated and discarded. Her decomposing remains were discovered in bin bags on the banks of a river in Kilkenny in 2004, shocking and scaring the community in equal measure. Only when Paiche Onyemaechi's identity was confirmed did one of Ireland's most gruesome and unsolved murders begin to unravel.

In life, the 25-year-old was renowned for her beauty. In death, her killers desecrated her image in a crude attempt to almost nullify her very existence. Her head has never been found. In her short but complicated life, the young Malawian woman meant many different things to the people she shared her life with. To her two young sons, she was a loving mother. To her father, the chief justice of Malawi, she was a wayward, strong-willed child. To TJ Carroll, then one of Ireland's wealthiest pimps, she was an extremely lucrative prostitute.

And to her second husband Chika – who disappeared days after her headless body was discovered on the banks of a bridge in Kilkenny – she was less than the dutiful wife he desired. A couple of weeks after he disappeared, gardaí intercepted two packages addressed to Nigerian-born Chika. One was sent from Belgium, the other from Austria, and neither had a return address. Both packages contained jars filled with liquid, twigs and earth. The parcels baffled gardaí. Following analysis, the substances in the jars were deemed to be natural soil-based matter and fluid. Senior detectives probing the case now believe the Malawian woman was murdered in a ritualistic killing and her head was offered up as a sacrifice.

On 10 July 2004, Chika walked into Waterford garda station and reported his wife missing. The couple had moved from Dublin to Waterford in May 2001 after Paiche left her first husband, Malawian Abiodun Lambe, for Chika. In a statement to gardaí, he said his wife had left their home in Herblain Park, Waterford city, two nights earlier to go to Limerick in search of work. He gave them a photograph of Paiche.

Chika told gardaí he'd spent the day with his wife and their two young sons, Anthony and Andrew, who were three years and 18 months old at the time of their mother's murder. That evening, after the family ate dinner, he "made love" to his wife, who later received a phone call at 9pm, he told gardaí. At 9.30pm, she left the house abruptly to go to Limerick and he hadn't seen her since.

Two days later, Chika met detective garda Gerry Howe by appointment at the station to give a more detailed statement about his wife's disappearance. But he gave a different timeline and version of events, which raised eyebrows among gardaí. Chika also told Howe that his wife worked as a prostitute and that she'd often go away for a week at a time to "meet men" for "lots of loving".

Once, he said, she was dropped home by a man driving a black BMW. Detectives later established that this car belonged to wealthy pimp TJ Carroll, who Paiche worked for. At the time of her murder, he was one of the most well-established pimps in Ireland. His fortunes have since waned. The Carlow man was jailed in 2010 for running a multi-million euro prostitution ring.

Detectives probed extensively to find out if Carroll was involved in the young mother's murder but have now ruled him out as a suspect. What use would one of his most profitable prostitutes be to him if she was dead? The Carlow man was running a major prostitution ring at the time and Paiche was one of the few girls he considered important enough to personally drop home. Everything Chika told the detective was taken down in a statement and his young wife officially became a missing person. At that stage, there was no reason whatsoever to believe she was dead.

But 13 days after Chika reported his wife missing, her dismembered body was discovered in bin bags on the banks of Brenar Bridge in Kilkenny. Local gardaí were stunned when they uncovered the decapitated body of a black woman in bin bags. She was fully clothed and there were no other injuries on her body. From the positioning of her body, she was most likely thrown from the bridge. On the other side of the canal bank, Paiche's vanity case containing some of her jewellery was discovered. Detectives believe her killer may have discarded it to give the impression that the 25-year-old had been murdered in a botched robbery. Gardaí do not believe theft was the motive for the murder.

Her body was eventually identified through fingerprints and it then emerged that Paiche had several identities. According to the fingerprints, the remains belonged to Regina Vasslatos from Mozambique. When she arrived in Ireland as an asylum seeker in 1999 with her first husband, this was the false name she gave. She also regularly used the names Gina and Cassandra. Paiche's mother's maiden name was Willis and after her murder, gardaífound a forged French identity card at her home that stated her name was Gina Willis. The 25-year-old's various identities complicated an already puzzling murder.

She was born Paiche Unyolo in Malawi on 14 April, 1979. One of five children, her father, Leonard Unyolo, was the chief justice of Malawi at the time of her murder. She met her first husband, Abiodun Lambe, when she was a teenager and married him despite her father's opposition. The couple left Malawi in 1999 and lived in the UK briefly before arriving in Dublin seeking asylum, on the basis that they faced persecution in their homeland. But the marriage was not destined to survive. Paiche met Chika Onyemaechi at a Dublin hostel in 2000 and struck up a friendship with the Nigerian that would eventually lead to an affair. In March 2001, Paiche left her husband for Chika.

Paiche and Chika soon decided they wanted to move out of Dublin and chose Waterford as the place to begin their new life. Paiche had also fallen pregnant by her new boyfriend. Anthony Leonard Onyemaechi was born in August 2001. His middle name is the same as his grandfather's, suggesting that although Paiche and her father had a troubled relationship, she still felt an attachment to him. In November 2001, the couple were married at the registry office in Waterford. Strangely, although Paiche had married Abiodun in Malawi, the paperwork had not been filed correctly so technically she was still a single woman. While there is no doubt that the ceremony to her first husband took place, it was not recognised officially in her home country, which is beset with corruption.

The family settled at 27 St Herblain Park in August 2003. It was to be the last place Paiche would call home. By then, the young parents had welcomed another son into their family. Andrew Kuzoni Onyemaechi was born on 12 April 2003.

The couple were granted full refugee status following the birth of their sons. It didn't take Chika long to secure employment in Waterford. At the time of his wife's death, he was holding down two jobs. He was working in an Italian-run takeaway as well as the Tower Hotel in Waterford city. In both places of employment, his employers and co-workers knew him as Patrick Jack. Chika was reasonably well-liked by Irish people but many Africans living in Waterford expressed reservations about him.

But everyone loved Paiche. She was known to always have a kind word for everyone around the town. She became involved in prostitution soon after she arrived in Waterford and gardaí believe her husband introduced her to this murky world. She had a few regular clients in Waterford whose homes she visited for sex. One of these men was an Italian who worked with her husband at the takeaway. He later told gardaí he handed over €120 each week to Chika to have regular sex with Paiche.

Paiche's life began to change when she met a Middle-Eastern woman, also a prostitute, who encouraged her to work outside Kilkenny. They became friends and she told Paiche that she was beautiful enough to be earning thousands each week. This woman introduced Paiche to TJ Carroll and one of his associates, who happily took her on.

Soon, the two women were travelling around the country together to work in various brothels and massage parlours in Galway, Limerick, Carlow and Kilkenny. Chika initially encouraged his wife, as she was now earning considerably more money, much of which was handed over to him. But being away from her husband for a week at a time was also giving Paiche a new sense of independence.

When the 25-year-old's headless body was discovered, her husband was contacted to identify the body. It was 23 July 2004. The next day, Chika boarded a bus bound for Dublin, effectively abandoning his two young sons. He has not been seen since. Detectives believe the Nigerian is now most likely living in the UK. Despite appeals, he has not come forward to assist gardaí.

Paiche's father and other members of the family flew to Ireland upon receiving the news of her murder. The family decided her burial should take place in Waterford. A couple of days before the family returned to Malawi – bringing with them Anthony and Andrew to be raised far away from the country where their mother lost her life – chief justice Unyolo met with the then justice minister Michael McDowell to discuss his daughter's murder. The meeting was at the request of the Malawian. Detectives found Paiche's family to be respectable people, deeply shocked by the brutality of her murder. But when gardaí told them that she was involved in the sex industry, her family found this difficult to accept. They simply refused to believe it.

After Paiche's funeral, detectives continued with their enquiries. Suspicious of Chika, gardaí interviewed everyone the Nigerians came into contact with from the day he reported his wife missing to the day he himself disappeared. It soon emerged that Chika had given his friends and co-workers wildly varying accounts concerning his wife's disappearance. At the home of an African couple his wife was friendly with, he telephoned Paiche's sister Lucy in Belgium. He told his wife's sister that she wore "dirty clothes, prostitute's clothes... I pray that they will kill her and she will not return to me." After the telephone conversation ended, Chika told the couple he was happy to be living as a bachelor. He then asked them: "If you kill someone and put them in the river, will the police detect it?"

Shortly before her death, Paiche had confided to this couple that she was tiring of life as a prostitute and was considering moving back to Malawi with her sons. The next day, Chika bumped into a Nigerian acquaintance. He told his fellow countryman that his wife had gone to Limerick to work in lap-dancing clubs and massage parlours. "Limerick is a dangerous place, they could kill her," he said.

A couple of days later, Chika met a Nigerian woman in Waterford that he took a shine to. "I'm a bachelor looking for a girlfriend," he told her. "My wife ran away back to Malawi to marry a rich man." The 31-year-old seemed unable to keep his own counsel – he told three other people separate stories about where his wife had gone.

It was of particular interest to gardaí that Chika was in regular contact with a Nigerian named Chijioke Ezekwem, known as CJ, who lived in Galway. The pair were from the same Igbo tribe in Nigeria and grew up together. They were akin to blood brothers. The week before Paiche disappeared, the couple had a fight and Chika left Kilkenny to visit his friend for a few days. Detectives believe that CJ then came back to Waterford with Chika on 7 July. Chika went home to his family while CJ stayed somewhere locally in Waterford for a few days. Three days later, Chika reported his wife missing.

The murder inquiry was extensive and all avenues were explored. When gardaí intercepted packages in the post addressed to Chika that contained soil-based matter and fluid shortly after his disappearance, at first they were stumped. But gardaí now have a theory about what was the intended purpose of these substances. Their belief is that she was killed in a ritualistic murder and those who beheaded her offered her head up as a sacrifice, believing it would bring them riches. Gardaí researched beheadings in Africa and found that similar decapitations still take place within tribes in various parts of the continent. Gardaí also suspect that more than one person was involved in her murder.

Over two years after her dismembered body was discovered, gardaí charged CJ with withholding information in relation to Paiche's murder. But this charge was later withdrawn due to insufficient evidence. Gardaí believe Chika, a former professional footballer, is unlikely to return to Ireland as he is still sought here for questioning in relation to his wife's murder. But even if gardaí establish his whereabouts, there is insufficient evidence against the Nigerian to extradite him to face charges.

The couple's sons, Anthony and Andrew, are Irish citizens and will have the right to return to Ireland if they so wish. While Andrew was just 18 months when his mother died and his father disappeared, he probably has little recollection of his early life in Ireland. But as Anthony was three years old, he would have clearer memories of his life in Waterford. As they grow up, both children will ask questions about how their mother lost her life. And why their father then disappeared without a trace and they have never heard from him since.

Six foreigners brutally murdered in Ireland

'Passport to Murder' gives the inside story behind the murders of 22 foreigners in Ireland. Cases covered include:

Farah Swaleh Noor

The killing of Farah Swaleh Noor by the 'Scissor Sisters' is infamous, but what about the life and crimes of the Kenyan before his gruesome death? Noor was previously a violent sexual predator.

Manuela Riedo

Swiss student Manuela Riedo was murdered in a vicious assault in Galway that appalled the country. Her killer, Gerald Barry, has a history of sexual violence against women but was free to roam the streets. Barry, a career criminal, had raped a Frenchwoman just seven weeks before he murdered the 17-year-old student.

Pawel Kalite and Mariusz Szwajkos

The screwdriver murders of Polish mechanics Pawel Kalite and Mariusz Szwajkos by teenager David Curran were fuelled by drink and drugs. They were murdered when Curran stabbed them with lethal precision through their skulls.

Baiba Saulite

The execution of Latvian Baiba Saulite by a Dublin crime gang on the orders of her imprisoned husband sent shockwaves through Irish society. Lebanese national Hassan Hassan ordered his estranged wife's murder to win sole custody of their two sons. The criminal escaped conviction for involvement in his wife's death and has now left Ireland with his two boys.

Regina O'Connor

Rwandan Regina O'Connor was brutally murdered by her drug addict son Moses, who is now serving a life sentence. Moses was weeks from his 25th birthday when he killed his mother. Regina's will stated he would receive his inheritance when he turned 25 on the strict condition that he was
drug-free, a possible motive for his crime.

Book Details

This is an edited extract from 'Passport to Murder' by Ali Bracken, published by Gill & Macmillan, priced at €12.99