GUANTANAMO Bay detainees, including David Hicks, were forced to take high dosages of anti-malaria drug mefloquine despite showing no signs of the disease, a practice likened to ''pharmacological waterboarding'' by a US military doctor.

Questions have been raised about whether the mass administration of the drug to detainees was a secret, illegal experiment after a medical journal article last month by an army doctor, Major Remington Nevin, highlighted the ''inappropriate use'' of the drug and asked if its use had been motivated by the drug's psychotic side effects.

David Hicks in Sydney recently.

The US Centres for Disease Control issued a warning against the use of mefloquine on anyone suffering psychiatric disturbances or having a previous history of depression. Dr Nevin also warned high doses of the drug could cause brain injuries.

Mr Hicks has long claimed he was drugged against his will. Evidence including previously secret reports and witnesses including a Guantanamo guard and New York lawyer Josh Dratel support Mr Hicks' claims.