WASHINGTON - Osama bin Laden was buried at sea from a US warship amid high secrecy that included his body being referred to as "the package" delivered by "Fedex", an American courier delivery services company, secret military emails reveal. "Any sailors watch the burial?" a Navy commander asked the public affairs officer on the USS Carl Vinson in a May 3, 2011, e-mail. The Carl Vinson was the carrier where the SEALs took bin Laden's body by helicopter after he was killed during the May 2, 2011, raid at his hideout in Abbottabad.

"Only a small group of the leadership was informed -- less than a dozen," the public affairs officer replied. Another e-mail stated, "Burial No Sailors Watched."

The emails were obtained by the Associated Press, the American news agency,  under freedom of information. The news agency said they were heavily blacked out but nonetheless offered the first public disclosure of government information about the al-Qaeda leader's death, and his sea burial after performing Islamic rites.

One email stamped secret and sent on 2 May by a senior navy officer briefly describes how bin Laden's body was washed, wrapped in a white sheet, and then placed in a weighted bag.

"Traditional procedures for Islamic burial was followed," the 2 May email from Rear Admiral Charles Gaouette reads. "The deceased's body was washed (ablution) then placed in a white sheet. The body was placed in a weighted bag. A military officer read prepared religious remarks, which were translated into Arabic by a native speaker. After the words were complete, the body was placed on a prepared flat board, tipped up, whereupon the deceased's body slid into the sea." Earlier, Gaouette, then the deputy commander of the navy's Fifth Fleet, and another officer used code words to discuss whether the helicopters carrying the Seals and Bin Laden's body had arrived on the Carl Vinson.

"Any news on the package for us?" he asked Rear Admiral Samuel Perez, commander of the carrier strike group that included the Vinson.

"Fedex delivered the package," Perez responded. "Both trucks are safely en route home base."

The emails include a reference to the intense secrecy surrounding the mission and why few records were held. "The paucity of documentary evidence in our possession is a reflection of the emphasis placed on operational security during the execution of this phase of the operation," Gaouette's message reads.

Recipients of the email included Admiral Mike Mullen, then the chairman of the joint chiefs of staff, and General James Mattis, the top officer at US Central Command. Mullen retired from the military in September 2011. The Obama administration has kept a tight hold on materials related to the Bin Laden raid. The AP said that in response to separate requests from the AP for information about the mission, the defence department replied in March that it could not locate any photographs or video taken during the raid or showing bin Laden's body. It also said it could not find any images of bin Laden's body taken while it was on board the Vinson.

The Pentagon said it could not find any death certificate, autopsy report or results of DNA identification tests for Bin Laden, or any pre-raid materials discussing how the government planned to dispose of bin Laden's body if he were killed. The defence department also refused to confirm or deny the existence of helicopter maintenance logs and reports about the performance of military gear used in the raid. One of the stealth helicopters that carried the Seals to Abbottabad crashed during the mission and its wreckage was left behind. People who lived near bin Laden's compound took photos of the wrecked chopper.

The AP has lodged an appeal requesting more information from the defence department. The agency said the CIA, which ran the bin Laden raid and has special legal authority to keep information from ever being made public, had not responded to requests for records about the mission.