American football star Antonio Brown has been accused of rape by his former personal trainer.
Britney Taylor, who decided to forgo anonymity, said Mr Brown sexually assaulted her on three occasions, according to a civil lawsuit she filed.
The 31-year-old has denied the allegations.
Mr Brown's new team, the New England Patriots, said that the National Football League (NFL) was also launching an investigation.
What does the lawsuit say?
The complaint says that the two met at a bible study class at Central Michigan University in 2010.
Mr Brown later hired Ms Taylor, who is a gymnast, in 2017, to improve his ankle flexibility.
However, according to the lawsuit, he sexually assaulted her twice in training sessions in June 2017, and she stopped working with him.
On one occasion, she says Mr Brown assaulted her while the two were streaming a church service on Ms Taylor's iPad in Mr Brown's Miami home.
The lawsuit reads that Mr Brown "reached out to Ms Taylor, expressing contrition, begging forgiveness and pleading with her to train him again".
She reluctantly agreed but in May 2018 he raped her, according to the court papers.
Her lawsuit says that Mr Brown later sent her "astonishingly profane and angry text messages" bragging of his alleged sexual assault against her.
In a statement, Ms Taylor said "deciding to speak out has been an incredibly difficult decision" and that she has "found strength in my faith, my family, and from the accounts of other survivors of sexual assault".
"Speaking out removes the shame that I have felt for the past year and places it on the person responsible for my rape," she said, adding that she will "co-operate with the NFL and any other agencies".
What has Mr Brown said?
Through a lawyer, Mr Brown said that he was first approached by Ms Taylor in 2017, after he signed a contract making him the highest paid wide receiver in the NFL.
He said that Ms Taylor asked him to invest $1.6m (£1.3m) in a "business project" and later cut off contact with him after he refused. She "resurfaced" in 2018 with an offer to train Mr Brown, he said.
"Mr Brown denies each and every allegation in the lawsuit," his lawyer, Darren Heitner, said in a statement. "He will pursue all legal remedies to not only clear his name but to also protect other professional athletes against false accusations."
Mr Heitner added that "any sexual interaction... was entirely consensual." On Twitter he suggested that Mr Brown may issue a counter-lawsuit against his accuser.
Antonio Brown will leave no stone unturned and will aggressively defend himself, including exercising all of his rights in countersuits.— Darren Heitner (@DarrenHeitner) September 11, 2019
Mr Heitner added Ms Brown has "continually posted" photos of his client on social media "in an effort to financially benefit from his celebrity".
"Mr Brown, whose hard work and dedication to his craft has allowed him to rise to the top of his profession, refuses to be the victim of what he believes to be a money grab," he said.
Mr Brown has been in the press this week after publicly demanding on Twitter that the Oakland Raiders release him, and later receiving a reported $9m signing bonus for the New England Patriots.
The Patriots said in a statement, in response to the lawsuit: "We take these allegations very seriously.
"Under no circumstances does this organisation condone sexual violence or assault... We will have no further comment while that investigation takes place."
Patriots head coach Bill Belichick on Wednesday declined to comment on the lawsuit, but said Mr Brown would be at practice. He did not confirm if Mr Brown would play on Sunday, when the Patriots play the Miami Dolphins.
"We're taking it one day at a time, just like we always do," Mr Belichick said at a news conference.
The NFL is reportedly considering placing Mr Brown on the commissioner's exempt list, which would bar him from playing for the Patriots, people familiar with the matter told the Washington Post.
While on the list, players cannot attend practice or games but they are still able to receive their normal salary and use team facilities, according to the NFL.