In an unusual confrontation of actor vs actor, Stephen Baldwin has just filed a lawsuit in Louisiana Federal Court alleging that Kevin Costner and his business partners "tricked" him into selling shares vested in Ocean Therapy Solutions.

For those who followed the Gulf oil spill drama, you might remember that Ocean Therapy Solutions is the company Kevin Costner acquired from the U.S. government in 1995 for around $24 million. The firm specializes in developing centrifugal oil-water separators, something the 55-year-old actor became interested in commercializing after witnessing the '89 Exxon Valdez oil spill.

For more than 15 years, Costner found it difficult to sell the machines — that is, until the Deepwater Horizon oil spill this summer prompted BP to purchase some 32 of the devices. This resulted in millions in new business for Ocean Therapy Solutions — as well as some promising business partnerships worth even more.

Enter Stephen Baldwin's lawsuit. Official documents acquired by TMZ paint a fascinating picture of behind-the-scenes deals in the wake of the Horizon disaster. Before the spill, Baldwin alleges that he was told Costner had actually sold off his interest in the centrifuge technology, apparently frustrated with an inability to market them and what he perceived as a losing venture financially.

But somehow, this wasn't the case — and as he would later learn, Costner was still heavily invested with his business partners. Still, Baldwin was given 10 percent of Ocean Therapy Solutions in late April. Most likely due to some personal financial setbacks (as well as a belief that the company was failing), the actor sold off those shares, but claims in the lawsuit that he and another partner were never told of any impending contracts with BP, in particular one worth more than $52 million.

The lawsuit also alleges some pretty massive fraud on the part of the majority holders of OST in an effort to hide business transactions, as well as the use of money from BP to muscle out the minority players (all without any of these investors, including Baldwin, knowing that there was massive profit being generated in the first place).

If it stands, it looks like this one could get pretty messy. Baldwin is suing for unspecified damages, but at the very least it appears that he's owed $3.8 million, which is way beyond the $500,000 he claims he was paid for his 10 percent ownership.

Neither Ocean Therapy Solutions nor Costner have yet commented on the case.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Stephen Baldwin suing Kevin Costner over oil spill tech
In a bizarre twist, actor claims Costner duped him into selling shares in company that separates oil from water.