Lawyers representing Richard Pryor, Jr. have sent a cease and desist letter to the star's widow Jennifer Lee Pryor, who is contributing to the film biopic, urging her to stop work on the project amid a dispute over name rights.
In the letter, obtained by Tmz.com, the star's son accuses his stepmother of using "illegal, fraudulent" activity to obtain the rights to her husband's name. He is also reportedly threatening to take legal action if the biopic moves forward.
Rapper/actor Nick Cannon has been linked to the lead role in the movie.
Pryor died in 2005 aged 65 after suffering a heart attack. He spent years battling multiple sclerosis prior to his death.