In the school photo that her parents gave to a missing children's website, Tanya Kach looks sullen and defiant. A teenager experiencing the hellish hormones of adolescence combined with the break-up of her parents' marriage. Her bright blue eyes and mouth held in a straight line reflect the sort of surly attitude of teenagers. Her blonde hair is semi-permed, a rebellion against authority, or betraying a desperation to be all grown up. This was in 1996.

Ten years later Tanya Kach is all grown up.

Physically she looks older than her 24 years but gone are the defiant eyes, the rebellious attitude. Even her peroxide blonde hair can't brighten the haunted face and heavily rimmed kohl eyes that peered out nervously at reporters and cameras when she spoke about her life with Thomas John Hose.

Hose was the security guard at Cornell middle school that Kach attended. Kach claims Hose had kept her prisoner in his parents' house for 10 years. In one of the most bizarre tales ever of kidnapping and exploitation, Kach alleges that Hose preyed on her vulnerability and stunted self esteem with mind games by threatening to kill her if she ever left or told anyone who she really was.

She claims she was held as a virtual sex slave, and that he consistently told her over the years that she was stupid, that her parents didn't want her and that he was the only one who cared anything for her.

Kach says she was forced to live in his second-floor bedroom and could only associate with those living in the home. When anyone visited she had to stay in her room. For a bathroom she was given a bucket. She was left a supply of bottled water and was fed whatever he chose to bring her. She wore second-hand clothes.

Each of their sexual encounters, which began soon after he brought her to his house, was recorded on a calendar diary by her at his instruction. This, she said, was so he could brag to friends and colleagues.

She was not allowed leave the house until 2000 and never at night time.

Lawyers for Hose argue that Kach could have left whenever she wanted. But so diminutive was Kach's confidence that the furthest she ever ventured was JJ's deli mart, a local corner store two blocks from the Hose house.

There she'd buy small miscellaneous things like chewing gum or soft drinks.

The elderly owner of the store, Joe Sparico, would eventually be her saviour.

Over time, Sparico's curiosity was peaked by the air of depression around the always neatly dressed young woman who seemed to hang around his store as if wanting to talk.

Yet she never said very much. As was his way with customers, Sparico tried to engage Kach in brief and friendly conversation, asking who she was and where she lived.

The girl, over the course of six years, told him her name was Nikki Allen and that she lived nearby.

She confided more and more in Sparico during her brief visits to the deli. Then one day three weeks ago she launched into a story that seemed almost too incredible to be true.

Her name wasn't Nikki Allen she said, but Tanya Nicole Kach, and she was listed on a missing children's website.

To Sparico and most anyone else in the small community, the name was vaguely familiar. Tanya Nicole Kach had disappeared 10 years before from an area of McKeesport, a city of 24,000 residents 15 miles from Pittsburgh, Pennsylvania.

On 10 February 1996 and for several months afterwards, Kach had made occasional local headlines after mysteriously vanishing from her father Jerry Kach's home.

But some in the area weren't overly perplexed. Kach had been, according to Cornell middle school authorities, a troublesome teen with few friends, who had run away from home before.

For about a year there were public appeals for information on her whereabouts, and local parents fretted about their own children's safety.

Stories circulated at the time that Kach had left because of troubles at home.

Her parents were going through a messy divorce and a stepmother had been introduced at the same time that Kach was getting out of control and rebellious. The stepmother described the 14-year old as "streetwise".

There was talk that despite her tender years she'd already been involved in sexual relationships, something Kach would seem to deny as she claims Hose took her virginity.

Further rumours abounded that Kach had had a crush on a man who worked at her school. It was hardly a secret. Kevin Churchfield . . . a local man for whom she had babysat . . . said that she confided in him her childish infatuation with Hose. School peers reported that Hose walked Kach to classes and there was gossip that the two were dating, though few gave it much credence.

Though Hose was questioned at the time of Kach's disappearance, the police dismissed him as a suspect in part due to a good reputation. In fact few involved with Cornell middle school would have believed it possible he could do anything wrong, so highly regarded was he at work.

In 1999, when Kach had already been at Hose's home for three years, the school celebrated 'Thomas Hose Day' and presented the security guard with a plaque in honour of his work protecting his young charges' safety.

The reality of his home life couldn't have been further from people's suppositions, if Kach's story is to be believed.

Referring to Hose in court in McKeesport last week, an altogether more confident Kach told the court: "There were a few times that he got into my face and said, 'You go or tell anyone and I'll kill you.'" Local police superintendent Charles Moffatt told reporters that by the time authorities were alerted, Kach wasn't being held against her will; Hose had effectively brainwashed her and changed her appearance to keep her where he wanted her.

Joe Sparico told his son about Kach. The younger Sparico was a retired police officer who recognized Kach's name. Sparico went to authorities with the information the girl had given him at the end of March.

"She'd come up to get a pop, a tea, a paper. . . she'd confide in me, " Sparico said.

"She wanted to be wanted, that's all."

After investigation, police have concluded that, in essence at least, Kach's tale is true.

Yet many can't grasp why or how Kach went home with Hose in the first place. She has allegedly told authorities that after playing truant at school one day in 1995 she was caught by the security guard.

They huddled in a stairwell and started kissing before hatching a plan for her to leave home and live with him she says. She moved in on 10 February 1996, the same day her parents reported her missing.

Whatever the true nature of Kach's story, her reunion with her parents after 10 years was heartfelt and emotional. Her mother Sherri Koehnke, who had moved away and remarried since her daughter's disappearance, told reporters: "It's the best ending I could have thought about when I thought about what could have happened to her."

Grasping her father's hand shortly after they'd been reunited, Kach told the press:

"He's crying, I'm crying. All he kept saying was, 'I got my baby.' I'm touching blood, and I get to say, 'I love you Dad.'" Her father Jerry Kach echoed her sentiments: "I just say thank you; there is a God and he brought my little girl back home."

Hose, now 48, has been suspended without pay from Kach's school where he had continued to work, and is charged with statutory sexual assault and involuntary deviant sexual intercourse.

His friend, beautician Judith Sokol (57), has also been charged in the case. Kach claims Sokol was aware of Hose's detention of her and of their sexual relationship and that she was the one who cut and dyed the 14-year old's hair to disguise her initially.

"I went back and forth between the houses at night, " Kach told the court, referring to Hose and Sokol's home.

"I lost my virginity in that attic while she was there. She was asleep."

Kach's lawyers are requesting that Hose not subject Kach and her family to the ordeal of a trial.

If that happens, the case may not be so cut and dried.

Hose's attorney James Ecker has said: "I don't think you'll find anybody in the United States who says she was held against her will."

Hose's defence lawyers are further arguing that Kach wanted to marry Hose, and that she could easily have left but instead begged to stay with him.

Many observers are sceptical that Kach's relatively groomed appearance, regularly dyed hair and manicured nails are those of a prisoner.

Others wonder why she didn't call police or her parents even if she wasn't on good terms with them over the years, or indeed how she failed to be spotted by someone who knew her in the area.

Some suggest that she was never a prisoner and that, with the demise of her expectations of a better life with Hose, she sought a sort of revenge by turning him in as a cruel and malevolent captor.

Both Thomas Hose and Judith Sokol deny the charges and have been released on bail.

In an ironic twist, Hose is now under house arrest in the very same home where he allegedly kept Kach prisoner for all those years.

The truth will be decided by the courts in the coming months.