An unreleased Pentagon report provides new details concluding that one in seven of the 534 prisoners already transferred abroad from the detention centre in Guantanamo Bay,Cuba,has returned to terrorism or militant activity,according to administration officials. The conclusion could strengthen the arguments of critics who have warned against releasing any more prisoners as part of US President Barack Obamas plan to close the prison by 2010. The Pentagon promised in January that the latest report would be released soon,but Bryan Whitman,a Pentagon spokesman,said that the findings were still under review. Two administration officials said the report was being held up by Defence Department employees fearful of upsetting the White House,at a time when even congressional Democrats have begun to show misgivings over Obamas plan to close Guantanamo. Pentagon officials said there had been no pressure from the White House to suppress the report. The report is the subject of numerous Freedom of Information Act requests from news media organisations,and Whitman said that he expected it to be released shortly. The report,a copy of which was made available to The New York Times,says the Pentagon believes that 74 prisoners released from Guantanamo have returned to terrorism,making for a recidivism rate of nearly 14 per cent. The report confirms that two former Gitmo prisoners Said Ali al-Shihri,a leader of al-Qaedas Yemeni branch,and Abdullah Ghulam Rasoul,an Afghan Taliban commander have indeed returned to the fight.