Stephen Baldwin is suing fellow actor Kevin Costner over their investments in a device which BP used to try to clean up the massive Gulf of Mexico oil spill.
A federal lawsuit filed in New Orleans by Baldwin and a friend claims Costner and a business partner duped them out of their shares of an 18 million dollar (£11.7 million) deal for BP to buy oil-separating centrifuges from a company they formed after the April 20 spill.
BP ordered 32 of the centrifuges, which separate oil from water, and deployed a few of the devices on a barge in June.
Costner's publicist, Arnold Robinson, declined to comment on the allegations.
The lawsuit seeks unspecified damages.