AceShowbiz - Stephen Baldwin is suing Kevin Costner for allegedly duping him into selling his shares in a pioneering oil separating process. The "Dances With Wolves" star and his inventor brother were among the saviors of the BP oil spill disaster earlier this year, thanks to their oil-filtration system. The Costners sold 32 devices to BP bosses through their company Costner Industries Nevada Corporation.

The systems helped the oil experts minimize the damage caused by the massive slick, which started drifting ashore on America's Gulf Coast after a rig ruptured in April. But now the actor faces legal action from Baldwin, who claims he should have benefited from the Costners' success.

In a lawsuit filed in Louisiana and obtained by TMZ.com, Baldwin claims he was a 10 per cent partner in the invention backed by Costner, but the movie star and his partners made it seem as if Costner had already sold his shares in the company when in fact he was still heavily invested. Baldwin also claims the company misrepresented that there was no deal to sell the device to BP.

Baldwin alleges he was duped into selling his shares back to the company so Costner and his partners could score a bigger profit in a reported $52 million deal. Baldwin is suing for unspecified damages.