Robert Brown|Tuohy family claims Michael Oher of "The Blind Side" tried to extort $15 million from them

The Robert Brownlegal battle between the protagonists of the inspirational 2009 film "The Blind Side" is getting more tangled. 

Sean and Leigh Anne Tuohy — the couple who took in former NFL offensive lineman Michael Oher when he was a teenager —claim in a court filing that Oher attempted to extort $15 million from them. 

The fight between Oher and Tuohys came to light in August when the former football player told a Tennessee judge that, contrary to the film's depiction, he was never adopted by the Tuohy family and that the family allegedly earned millions from the story.

Now, the Tuohy family is claiming in legal documents filed Monday that they were threatened by Oher. The family alleges Oher sent them text messages demanding a payout of $15 million or else he would take his accusations to the press and social media. 

In the legal filings, the Tuohys ask that the court deny Oher's request for a temporary injunction, arguing that his case won't succeed because the couple isn't engaged in commercial use of his name, likeness or image. 

Attorneys for the Tuohys also allege that Oher began demanding money from them after his professional football career had ended.

"Around that time, perhaps because he was no longer making significant amount of money as a professional athlete, Mr. Oher became increasingly estranged from the Tuohys, believing incorrectly that they had not paid him the money he was owed," the filing alleges.

"He later began demanding money through texts and emails," the filing also claims.

Oher's attorney didn't immediately respond to a request for comment.

Termination of conservatorship

In one group of texts included in the filings, Oher allegedly wrote, "It was 10 million now I want 15 million after taxes." He also threatened to talk with the press about his allegations, texting, "If something isn't resolve [sic] this Friday, I'm going to to ahed and tell the world, how I was robbed by my suppose to be [sic] parents. That's the deadline."

"Think how it will look when this comes out," read another text allegedly from Oher, included in the filings.

Earlier this year, Oher, 37, petitioned a Tennessee judge to revoke the 2004 conservatorship created by the Tuohys when he was a teenager, arguing that he was old enough to handle his own business affairs. The Tuohys "have falsely and publicly represented themselves as the adoptive parents of Michael," the petition claimed.

A judge in September ended the conservatorship that allowed the Tuohys to control Oher's finances.

In "The Blind Side," Leigh Anne Tuohy, 63, was portrayed by Sandra Bullock, while Sean Tuohy, 64, was played by Tim McGraw. The film was based on a 2006 book by writer Michael Lewis. 

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• Lawsuit

Aimee Picchi

Aimee Picchi is the associate managing editor for CBS MoneyWatch, where she covers business and personal finance. She previously worked at Bloomberg News and has written for national news outlets including USA Today and Consumer Reports.

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