BP executives and the US government hoped we'd all buy their "It's not that bad" propaganda on the Deepwater Horizon oil spill. This week, gruesome images emerged that show the real story of those days in the Gulf of Mexico after the rig exploded in April 2010.

Pictures of endangered sea turtles, dead and smothered in crude oil, along with sperm whales swimming through an oil sheen, tell a very different tale from the one spun at the time by US officials. Back then, we were told that wildlife had largely escaped undamaged.

Tell us the whole story

Images taken by scientists at America's National Oceanic and Atmospheric Administration (NOAA) have finally been released, following a Freedom of Information Act request filed by Greenpeace in July 2010. But that raises a question: what else are they still hiding?

Take action: Let's demand the White House immediately publishes all the images, files and documentation – before they reach a settlement with BP. Sign the Greenpeace petition now.

Read more: Jason Mark, of Earth Island Journal, was one of the reporters in Louisiana covering the Deepwater Horizon disaster; he witnessed the government's attempt to hide the worst effects of the spill.