The retired NFL star, whose life inspired the film, claimed the Tuohy family tricked him into making them his conservators.
Retired NFL star Michael Oher petitioned a Tennessee court on Monday to terminate a conservatorship, alleging Leigh Anne Tuohy and Sean Tuohy lied about adopting him while making millions off his name.
Oher's supposed adoption out of grinding poverty by the Tuohys inspired the 2009 hit film The Blind Side -- starring Sandra Bullock and Quinton Aaron. The film is based on the 2006 book of the same name and centered around the Tuohy family taking Oher in and helping him both in school and in the classroom.
In documents obtained by ET, the 37-year-old claims Sean and Leigh Anne tricked him into making them his conservators less than three months after he turned 18 in 2004, allegedly telling him there was no consequential difference between being adopted and entering into a conservatorship, giving them legal authority to make business deals in his name.
Oher only learned in February that the documents he was asked to sign by the Tuohys, under the belief that it was part of the "adoption process," were actually conservatorship papers that would strip away his legal rights, the petition says.
The 14-page petition, filed in Shelby County, Tennessee, probate court, alleges that the Tuohys used their power as conservators to negotiate a deal with 20th Century Fox that paid them and their biological children -- Collins Tuohy and Sean Tuohy Jr. -- millions of dollars in royalties from The Blind Side, which earned more than $330 million. The petition alleges that all four members of the Tuohy family were paid $225,000 for the film plus 2.5% of the film's proceeds.
Oher claims that he "at no time willingly or knowingly" signed said contract, which gives away the "perpetual, unconditional, and exclusive" to his name, likeness, voice, appearance, personality, personal experiences, incidents, situations, and events taken from his life with no payment. The document has a signature that appears to be his, but "nobody ever presented this document to him with any explanation."
The former athlete claims that in the years since, the Tuohys have continued calling Oher their adopted son and have used that assertion to promote their foundation, as well as Leigh Anne's work as an author and motivational speaker.
The 2004 filings say that Leigh Anne and Sean, now both 63, "have all powers of attorney to act on his behalf" and that Oher "shall not be allowed to enter into any contracts or bind himself without the direct approval of his conservators."
The petition alleges that the Tuohys told Oher that because he was no longer a minor, the adoption paperwork was titled a conservatorship. "At no point did the Tuohys inform Michael that they would have ultimate control of all his contracts, and as a result Michael did not understand that if the Conservatorship was granted, he was signing away his right to contract for himself," the filing says.
The conservatorship was granted until Oher reached the age of 25 or until the court terminated the order, but the arrangement was never terminated, Oher's petition claims.
The petition asks that the court end the Tuohys' conservatorship and issue an injunction barring them from using his name and likeness. It also seeks a full accounting of the money that the Tuohys earned using Oher's name, and to have the couple pay him his fair share of profits, as well as unspecified compensatory and punitive damages.
In their 2010 book, In a Heartbeat: Sharing the Power of Cheerful Giving, Leigh Anne and Sean claim that they split the profits of the film "five ways," according to ESPN, who first reported the news.
While many have viewed The Blind Side as an inspirational tale since its 2009 release, Oher has previously expressed sorrow over how he's depicted in the film, particularly the way it depicts him as a student that struggles with academics.
"People look at me, and they take things away from me because of a movie," Oher told ESPN in 2015. "They don't really see the skills and the kind of player I am. This stuff, calling me a bust, people saying if I can play or not ... that has nothing to do with football. It's something else off the field. That's why I don't like that movie.''
"That's taken away from my football,'' he added. "That's why people criticize me. That's why people look at me every single play.''
The Tuohys did not immediately reply to ET's request for a statement or comment.