Rape counsellors in Northern Ireland have warned that they are seeing two new cases of so-called drug rape every week.

Rape drugs are substances which can be added to drinks but are not easily detected.

One of the drugs most commonly used in such attacks is Rohypnol - a powerful sedative which has now been made illegal without a prescription.

The result of spiking a drink is a complete loss of memory for several hours, which can be used to an attacker's advantage.

Painful consequences

The impact is immediate but the consequences can be painful and long lasting.

One victim said loss of memory haunts her because two hours are missing out of her life.

"To this day, I don't know who has done it to me. I don't know if its a complete stranger or whether it's somebody I know.

"It's very hard because I could walk down the street, and the person who has done this to me, would be able recognise me but I would not know them."

Another woman had a similar experience after she went to the home of a man she regarded as a friend.

"I couldn't remember anything whatsoever. I was sitting in the bath for about half an hour crying and trying to remember what happened to me.

"Nothing would come back, I was still shaking, I still could not see or walk properly. "

Exact figures on drug assisted rape are not available but the Rape Crisis Centre in Belfast say they deal with, on average, two new cases every week.

Eileen Calder from the centre said: "We are also getting an increasing number of calls from women or friends of women who have been drugged but have managed to get out of the situation.

"It is a big problem but we have to remember that the vast majority of women who are raped and abused are not abused and raped under the influence of drugs.

"It is very worrying because this is something that in some ways is fairly new.

"The reports started coming in about two or three years ago to us. At the beginning we were fairly incredulous of some of the stories we were hearing."

Difficult to report

She said it was much more difficult for a woman to report a drug rape to police, than a rape where drugs were not involved.

She also urged anyone who felt they might have been raped, not to wash or change clothes and get tested for drugs immediately if possible.

Drug expert Frank McGoldrick said: "Drug assisted rape is something that most females should be aware of, because all the statistics are showing that it is on the increase and has been for the past two years."

The RUC say drug rape is a small percentage of the sex crimes they deal with and say there is a need for vigilance but not panic.

But they are also urging young women to be alert to the dangers.

In the rest of the UK, drug rape support groups estimate about 2,000 women have been the victims of sexual assaults carried out after they had been slipped drugs to incapacitate them.

Police in England believe the crime is under-reported, as it is notoriously difficult to get a conviction for an offence which usually takes place without witnesses.