"Are you going to make love to me?" the woman's 49-yearold husband asked. She was tired. Sex would be sore, she said. But despite her answering "no", he lay on top of her and raped her. Immediately afterwards, he laughed and said "thank you".

Later that morning he acted as if nothing had happened.

She told him she was going to report the rape to gardai.

"They wouldn't be able to touch me, I'm your husband, " he replied.

The Central Criminal Court last month refuted that claim and convicted the man of raping his wife. He was declared a sex offender and is listed for sentence on 30 January. The Sligo man was first found guilty of raping his wife in 2002 but this was overturned in the Court of Criminal Appeal and a new trial ordered. His subsequent conviction on the same charge last month means that, in theory, while there have been two convictions on record, in practice, only one person has been found guilty of marital rape in the state.

But in the 16 years since rape within marriage was listed as a criminal offence, the Sligo man is the first husband to have been found guilty in court of the offence. Charges were brought in just four cases in that period.

Despite the solitary conviction before the courts, the woman, who is now legally separated from her husband, is among hundreds of thousands of Irish women who are sexually brutalised in their own homes. A new study for the Department of Justice, conducted by a leading British researcher, indicates that most rapes and sexual assaults are carried out by men against their partners, not by strangers.

In a sample study of women who were victims of physical abuse at the hands of their husbands or long-term partners, independent researcher Thangam Debbonaire found that 66% said they were victims of sexual assault or rape within their relationship.

One in every five adult women in the state is a victim of domestic abuse in her lifetime, according to Women's Aid. Correlated with the new research, this indicates that over 200,000 adult women in the state could have been subjected to rape and sexual assault, or forced to perform sexual acts, by abusive husbands or long-term partners in their own homes.

Debbonaire's research, 'An evaluation of work with domestic abusers in Ireland', was commissioned by the Department of Justice in 2003 and presented last September.

Unusually, it was not circulated among agencies working with abuse victims.

The findings should have significant consequences for future requirements in government research and legislative approaches to sexual assault, experts have told the Sunday Tribune.

Don Hennessy, clinical director of the National Domestic Violence Intervention Agency (NDVIA), said Debbonaire's findings are further evidence of the need for major investment in primary prevention and funding for research into domestic abuse, in particular into rape and sexual assault in abusive relationships.

Women's under-reporting of rape is a major problem, according to Kate Mulkerrins, legal coordinator of the Rape Crisis Network of Ireland (RCNI). The 2002 government-funded Savi report into sexual violence in Ireland indicated that just one in 10 rapes of women is reported to gardai.

Of these, gardai say they have 'detected' or identified the perpetrator in 75% of cases, Of these, just one-third of cases (or 2.5% of all rapes) are brought to court by the Director of Public Prosecutions.

If rape and sexual assault within marriage is so widespread, why is there such low reporting of the crime? Low conviction rates are likely to play a major part in discouraging women from reporting rape within marriage. Mulkerrins notes that there is so little research in Ireland into attrition in rape cases generally that it is simply impossible to know why so many women do not report it.

Conducting that research is difficult to say the least.

Given the nature of the crime and the victim's relationship with the perpetrator, many women appear to be reluctant to describe what has been done to them as rape.

"This report is shocking but does not come as a surprise to people involved in domestic violence research, " Mulkerrins says. "Rape and sexual assault are the classic features of what is essentially at the heart of domestic abuse . . . control and power over a woman.

It would be naive not to acknowledge that domestic abuse is a major problem and to think that, within this environment, a significant proportion of women are not experiencing unwanted sex."

Debbonaire said it was important to note that her study focused on programmes to deal with abusers and was not a critique of the gardai or of agencies in the Irish criminal justice system. Her research did not try to determine why there are so few prosecutions for marital rape.

However, an as yet unpublished study into garda handling of rape allegations by women shows alarmingly poor practice in the investigation of the claims.

The seminal study by Dr Stephanie O'Keeffe found that gardai are prejudiced against victims, believing that women from working-class backgrounds and those with addiction problems are likely to make false allegations.

O'Keeffe, a Surrey-based academic who is now chief researcher with Ireland's Crisis Pregnancy Agency, found that many gardai perceive their role "more as deciding if a rape allegation is true, as opposed to looking to corroborate the information". The study noted "stereotypical social categorisation" among some garda investigators, who believe working-class people are more likely to give false information.

There is little awareness among gardai of the interview techniques and skills that could elicit reliable testimony from a victim. This suggests that a significant number of files outlining allegations of rape, which may be forwarded by gardai to the DPP, are not resulting in prosecution due to badly obtained testimony from a rape victim.

O'Keeffe did 32 interviews with gardai of varying expertise and experience, in which they described how they conducted rape investigations.

O'Keeffe analysed how they conceptualise their role as investigators and how they make key decisions about individual allegations. She also interviewed women who made complaints of rape to gardai.

"Gardai need to treat abuse and violence within marriage as a crime, not as a domestic Sunday Tribune.

A report by Amnesty, 'Justice and Accountability . . . Stop Violence Against Women', published last November, indicates that, for many women who are beaten in the home, reporting the crimes against them increases the risks that they . . . and often their children . . . may face.

With waiting lists of up to three months for barring orders in some areas, it is not surprising that many women believe they may be safer not to report it, or indeed to withdraw their complaint once made. The 7.7% conviction rate arising from claims of domestic abuse made by women may also discourage victims from reporting allegations of rape.

Mulkerrins says she is continually astonished at how the issue of marital rape is avoided in public debate. But she hopes that much can be learned from the largest-ever study into attrition in rape cases, which is now being undertaken by Deirdre Healy, a researcher at NUI Galway, and which was commissioned by the RCNI and part-funded by the Department of Justice.

"We cannot overstate the need for women, and men, over the age of 18 who were victims of unwanted sex in the period since 2002 to contact the research team in strict confidence, " she says. "Information is a vital tool if we are to end the cycle of pain experienced by so many people."