The use of date-rape drugs may not be as widespread as previously thought, a study has warned.

The report, conducted by the Association of Chief Police Officers, Forensic Science Service and Sexual Assault Referral Centres, suggested that many victims of sexual assault may have just been extremely drunk.

The report examined alleged or suspected cases of drug facilitated sexual assault (DFSA) between November 1 2004 and October 31 2005 in the Metropolitan Police, Greater Manchester, Derbyshire, Northumbria and Lancashire police forces as well as the Walsall area of the West Midlands.

The study examined a total of 120 cases. In 119 of them, the victims had reportedly been drinking alcohol, although alcohol was only detected in 52% of cases. However, in 35% of the cases, blood alcohol levels were estimated to be more than 2 - 3 times the driving limit.

Controlled or prescribed drugs were detected in 48% of cases, with cannabis and cocaine being the most common - being present in 20% and 17% of cases.

Overall, there were only ten cases of suspected DFSAs in which a sedative or disinhibiting drug had been detected. However, rohypnol was not detected in any of the cases, while another date-rape drug GHB was only detected in two cases.

Dave Gee, co-author of the research and vice-chair of the ACPO Working Group on Rape, said: "This study is the first of its kind in the police service and demonstrates the difficulties faced when investigating offences of this type. The findings contained within the report will assist forces in investigations and also inform the wider public as to steps one can take to minimise the threat of becoming a victim. The police will continue to take any allegations of this nature very seriously as they do for all offences of rape."

However, the study was described as "unhelpful" by campaign group Women Against Rape. Speaking to BBC Radio 4's 'Today' programme, Ruth Hall from the group said: "There is a lot of moralism about women drinking that doesn't apply to men. People don't think that when a man gets drunk he should expect to be raped, but when a women drinks, it is heavily used against her in court."

(KMcA)