Former Australian terror suspect Mamdouh Habib says new WikiLeaks documents support his case.
Habib, who's suing Egyptian authorities for torture, says he could have admitted to things he didn't do.
"Egyptian Government, until now, deny that I was there. I have it in writing," he told the ABC.
Habib says he was set up and given drugs.
"Maybe some stuff happened by me under drugs, I'm not aware of it, to be honest," he said.
Habib was under "extreme duress" when he made the claims, according to a memo released by the WikiLeaks website.
Guantanamo officials said Habib was suspected of being a "money courier and a terrorist operations facilitator" with links to the 9/11 hijackers and conspirators in the 1993 World Trade Center bombing, AFP reports.
He was arrested in Pakistan following the September 11 attacks in New York and Washington and held for six months in Egypt under the CIA's controversial "extraordinary rendition" programme, where he made sensational admissions.
"While in the custody of the Egyptian government, under extreme duress," Habib boasted that he trained six of the 9/11 plotters in martial arts and "was en route to hijack a Qantas flight", his leaked prison file said.
A friend was going to conduct a simultaneous hijacking from Thailand, the file said, adding that Habib admitted having information "to be used to poison an unidentified river" in the US and had fought in Bosnia, Chechnya and Afghanistan.
I was lying: Habib
Habib later retracted all the statements and told officials at the US detention site in Guantanamo Bay that he had been "lying" to the Egyptians.
The memo lends weight to Habib's claims that he was tortured by Egyptian authorities. He is seeking compensation over the allegations in a lawsuit against ex-vice president Omar Suleiman and Mubarak's son Gamal.
Now 56, Habib was held at Guantanamo for two-and-a-half years before being released in January 2005 without charge.
He won an out-of-court settlement with the Australian government over his treatment earlier this year, after a court ruled that he could sue.
The terms are confidential, but Canberra has indicated that it did not admit legal liability.
According to his file Habib had prior knowledge of the September 11 attacks in 2001, and a 2003 plot hatched in Thailand to hijack and crash several planes into Singapore airport.
It claimed he also knew about a large-scale Australian extremist plot to attack power stations and military installations.
A Pakistan-born architect, Faheem Khalid Lodhi, was convicted by a Sydney jury and jailed for 20 years over the plot in 2006, which was uncovered during the investigation into French extremist Willie Brigitte.
Hicks named
The second Australian detained at Guantanamo, David Hicks, was also classed "high risk" according to his file, leaked Monday by Wikileaks, which claimed he had "direct involvement" with Osama bin Laden and other Al Qaeda leaders.
He trained at numerous "terrorist camps" in Afghanistan in "urban warfare" and was approached by Mohammed Atef, third-in-command of Al Qaeda's military operations "regarding his willingness to be a martyr" - an offer he declined.
Hicks was detained by Northern Alliance soldiers in Afghanistan after September 11 and originally faced charges of "conspiracy, attempted murder by an unprivileged belligerent and aiding the enemy," his file said.
Now aged 38 and living in Sydney, Hicks was ultimately convicted by a military commission of providing material support for terrorism after doing a plea deal.
He spent five and a half years in the US-run prison at Guantanamo Bay.
"The detainee is highly trained, experienced, and combat-hardened, which makes him a valued member and possible leader for any extremist organisation," Hicks's classified file said.
"It has been determined this detainee poses a high risk, and poses a significant threat to the US, its interests and allies."
