Jury selection was scheduled Monday for Stephen Baldwin’s federal lawsuit against fellow actor Kevin Costner over their investments in a device BP used in trying to clean up the huge Gulf of Mexico oil spill.

Both are expected to testify. U.S. District Judge Martin Feldman ruled last month that every litigant must be in court every day "because of the seriousness of the claims and issues raised by the parties" and in case of mid-trial settlement talks.

The federal lawsuit claims Costner and a business partner duped Baldwin and a friend out of their shares of an $18 million deal for BP to buy oil-separating centrifuges after the April 2010 spill.

Baldwin and his friend, Spyridon Contogouris, said they didn’t know about the deal when they agreed to sell their shares of Ocean Therapy Solutions, a company that marketed the centrifuges to BP, for $1.4 million and $500,000, respectively.

BP ordered 32 of the centrifuges, which separate oil from water, and deployed a few of the devices on a barge in June 2010. BP capped its blown-out Macondo well the following month and kept more oil from leaking until the well was permanently sealed in September 2010.