12 Years A Slave's director Steve McQueen and scriptwriter John Ridley have reportedly fallen out over writing credits.
The rift apparently began when John turned down Steve's request for a shared screenplay credit, and escalated over the awards season before coming to a head at the Oscars, reported The Wrap.
The filmmaker failed to thank the writer in his speech when he accepted the Academy Award for best picture, while John, who agreed to adapt the book for free before the film received funding, also made no mention of the director when he won the Oscar for best adapted screenplay.
!2 Years A Slave, which John adapted from Solomon Northup's biography, won three Oscar gongs on the night, including the best supporting actress gong for Lupita Nyong'o.
John's spokeswoman said she could not reach him for comment but that the writer had thanked the filmmaker in previous speeches.
John previously revealed that the pair were on friendly terms, and that Steve gave him free rein on the script.
"I absolutely enjoyed spending time with him, not just working on the screenplay but talking about film, cinema and art," he said.
"I found him to be quite the opposite (of demanding). He would certainly articulate things he felt strongly about, but beyond that he was like, 'You're the writer, you go write'."