Oil has been pumping into the gulf and causing an environmental catastrophe since an underwater explosion sank the Deepwater Horizon drill ship April 20.
The "Field of Dreams" and "Dances with Wolves" star has financially backed a team of scientists headed by his brother for 15 years in hopes of developing technology to clean up massive oil spills, ABC said.
One of the results of the work was the creation by Ocean Therapy Solutions of a powerful centrifuge intended to separate oil from water and pour the oil into a holding tank.
ABC said Costner and representatives of the research group demonstrated the invention for BP officials in New Orleans last week.
"I believe they'll want to do the right thing," Costner said at the time.
"We've agreed to test it," BP spokesman Mark Proegler told ABCNews.com Wednesday.