Mr Oher, 37, was taken in by Sean and Leigh Anne Tuohy when he was in high school in a story that inspired the book and 2009 Oscar-winning movie The Blind Side.
But the former NFL player has claimed that the adoption story behind the blockbuster was a lie, and that the Tuohy family made millions from his name after the film was released as a result of a conservatorship they had placed him in.
Mr Oher said the Tuohys misled him into signing the agreement in 2004 by telling him they would become his adoptive parents.
According to court documents, the couple used their position as conservators to agree to a deal that saw them and their two biological children paid for the Oscar-winning film, which starred Sandra Bullock and made more than $300m.
Mr Oher filed a petition to terminate the conservatorship which was granted by a Tennessee judge in September.
The petition said Mr Oher made no money off the film, which was released after he completed his college career. According to the petition, Mr Oher claims he does not recall signing any agreement for the rights to his life story. He said while the conservatorship agreement has a signature that appears to be his, “nobody ever presented this document to him with any explanation,” the filing says.
However, an accounting document filed by the Tuohys allegedly shows Mr Oher did make money from the film, with payments going back to 2007, a year after the book was released, up to the most recent payment this April.
The document also allegedly showed that members of the family, including Mr Oher, agreed to divide the proceeds of the film and the book five ways.
A further statement to accounting says the Tuohys “have never received any money as conservators on behalf of Michael Oher and further never had control over any funds or dealings on behalf of Mr Oher during the entire term of the conservatorship.”
The Tuohys have called the claims they enriched themselves at Mr Oher’s expense outlandish, hurtful and absurd, and claimed they never intended to adopt the former NFL player.
But Mr Oher claims he thought he was legally adopted before finding out that he was not in February.
“Mike didn’t grow up with a stable family life,” his lawyer previously said. “When the Tuohy family told Mike they loved him and wanted to adopt him, it filled a void that had been with him his entire life. Discovering that he wasn’t actually adopted devastated Mike and wounded him deeply.”
Mr Oher rose to stardom playing soccer for the University of Mississippi and then in the NFL.