The U.S. government deliberately blocked the release of documents and photographs that showed the true impact of the BP oil spill on whales in the Gulf of Mexico, Greenpeace said Thursday.

After obtaining access to e-mails and photographs under the Freedom of Information Act, Greenpeace said the Obama administration sought to strictly control information about the impact of the 2010 spill, Britain's Guardian newspaper reported.

The images dating back to June 2010 show the carcass of a young sperm whale - covered in crude and partially eaten by sharks - floating at sea about 123 kilometers (77 miles) south of the spot where the Deepwater Horizon oil rig exploded on April 20, 2010, an accident that killed 11 workers and triggered a massive oil spill, the paper said.

It added that the photographs were taken by National Oceanic and Atmospheric Administration personnel on board the research vessel Pisces.

The discovery led to an exchange of e-mails between officials on land and crew on board the research vessel, who were ordered to keep the information secret and obtain samples from the carcass to determine if the whale died as a result of the spill, according to the Guardian.

According to the newspaper, Greenpeace said the NOAA issued a press release about the dead whale, but the text was subsequently edited and shortened with the aim of downplaying the impact of the oil spill on whales.

The photographs and documents obtained by the environmental NGO were released during a week in which BP Plc asked a New Orleans judge to finalize its $7.8 billion settlement for damages caused by the spill, the Guardian noted, adding that BP still faces claims from the federal government for environmental damages.

"In the settlement with BP, an endangered species or any animal killed by the spill matters," Kert Davies, research director of Greenpeace, was quoted as saying. EFE