Drugs that can be bought in shops or easily made at home are likely to have been used in a spate of drug rapes in Hamilton, says the Drug Rape Trust.
Police are investigating nine cases in which women say their drinks were spiked with drugs. Rape investigations have beenstarted in four of the cases.
The legal drug gammahydroxybutyrate, better known as GBH, fantasy or liquid ecstasy, is available in many health, cleaning and manufacturing products.
Experts say it is not hard to make from recipes on the internet.
Trust vice-president Jenny Fenton said GBH was the drug that the trust was most worried about and the one most likely to have been used in Hamilton.
Other drugs linked to drug rapes include sedatives, tranquillisers and antihistamines.
The trust is working with Labour list MP Dianne Yates to make GBH illegal and to provide greater protection to drug rape victims by deeming them unable to consent to sex if they are under the influence of drugs.
Ms Fenton said a small group of "good-looking, smooth-talking" men were probably responsible for spiking drinks.
"It is probably the work of one or two guys who work together," she said. "One of them will start talking to the girl and be all nice and offer to buy her a drink, and the other will slip the drugs in."
Ms Fenton said there must have been witnesses to the spiking of drinks in city bars, "and unless they come forward it will continue".
Hamilton bars should consider installing security cameras to act as a deterrent, she said.
Detective Sergeant Mark Greene said if women suspected they had been drugged, they should have a blood test immediately and contact police.
