BP COO Doug Suttles and actor Kevin Costner, co-founder of Ocean Therapy
By Nick Allen, Los Angeles
The unlikely legal case centres on technology that Costner and his associates provided to help suck up oil following the spill in the Gulf of Mexico.
Costner, the Oscar-winning Hollywood star and environmental activist, has spent over 15 years developing machines designed to separate oil and water, 32 of which were bought for the clean up by BP.
The spill resulted from an explosion on the Deepwater Horizon rig and flowed for three months, releasing millions of barrels of oil into the sea and creating a giant slick.
Amid desperate containment efforts Costner appeared before Congress to describe how the oil separating machines worked and advocating their use.
Baldwin, 44, who starred in The Usual Suspects, claims he invested in a joint venture with Costner, 55, and others and that he owned 10 per cent of it
But he claims he was duped into selling back his share for just $500,000 having not been told that BP was buying the machines for $52 million.
Baldwin claims the venture made a profit of $38 million of which his share should have been $3.8 million (£2.5 million), so he lost out on $3.3 million.
Another member of the joint venture who claims to have had a 28 per cent share is suing for $9.2 million in a joint lawsuit with Baldwin against Costner and his business partner.
In the 31-page lawsuit obtained by TMZ, the celebrity news website, Baldwin and the other plaintiff claim they were "misled" into selling their interests in a joint venture called Ocean Therapy Solutions.
The lawsuit alleges: "The plaintiffs have been damaged directly by the misrepresentations and omissions of defendants in that they sold their membership interests for a fraction of their actual value."
Costner has declined to comment on the allegations.