The Government and Opposition have again voted down a Senate motion by the Australian Greens to conduct an independent inquiry into the then Government's role in David Hicks' detention in Guantanamo Bay.

Australian Greens spokesperson for Legal Affairs, Senator Penny Wright, said all Australians should be worried by the clear determination of both old parties to sweep David Hicks' case under the carpet and refuse any scrutiny of what part the Howard Government played in his detention and mistreatment.

"David Hicks was held at Guantanamo Bay for years without charge. He was subject to cruel and degrading treatment, kept in deplorable conditions and didn't have access to a lawyer for a very long time; all the while the Australian Government stood by and let it happen," Senator Wright said.

"On the weekend, we heard of chilling reports detailing the forced use of drugs such as mefloquine, which is known to cause psychotic side effects and brain damage, and of doctored medical records which had the names and doses of drugs given to inmates removed.

"During question time today I also asked the Government whether it was aware of these techniques, who knew that this was going on and for how long.

"The Government would not answer these questions, despite the clear evidence that is available in the public domain. It would also not provide any answers on what evidence David Hicks had provided that led to the proceeds of crime case against him being dropped back in July.

"In 2006 then Shadow Attorney-General, Nicola Roxon, consistently called for a fair trial for David Hicks and highlighted the important role of the Australian government in upholding human rights, fair process and the rule of law for our citizens. So why is the Government scurrying to avoid the questions it was asking when in opposition, and why will it not agree to a full, independent inquiry into how this abandonment of an Australian citizen occurred?

"It is clear the Greens are the only party determined to find out the truth about what happened to David Hicks, and we will continue to push to get to the bottom of this case, to prevent it from happening to Australians in the future."

A transcript of the defeated motion can be found here.