New evidence has emerged that all Guantanamo Bay detainees, including David Hicks, were drugged involuntarily with a substance that has a long history as a truth serum.

Recently declassified US documents revealing medical procedures have shown that scopolamine was administered to all detainees taken to the Cuban detention centre.

Drugged … Hicks. Credit:Jacky Ghossein

The documents, which were standard operating procedures for nursing staff, were obtained by the independent US news outlet Truthout, and reveal that the rationale for the drug's use on all detainees was to prevent motion sickness.

However, US military experts have said that scopolamine is not recommended for motion sickness because of its severe side effects.