(Reuters) – U.S. pro football player Michael Bennett is considering a lawsuit, he said on Wednesday, after he was held on the ground, handcuffed and threatened by Las Vegas police last month because he is African-American.

Bennett, a Seattle Seahawks defensive lineman, said on Twitter he was headed back to his hotel on Aug. 26 after the boxing match between Floyd Mayweather and Conor McGregor when he heard what sounded like gunshots and joined others in running away. Bennett said the police singled him out and ordered him to the ground.

“As I laid on the ground, complying with his commands not to move, (the officer) placed his gun near my head and warned me that if I moved he would ‘blow my fucking head off,’” he wrote.

Las Vegas police said on Twitter the case was under investigation. “Reserve judgment. We will address this publicly today.”

A second officer jammed a knee into his back so hard it made it difficult for him to breathe before he was cuffed, the 6-foot 4-inch, 274-pound Bennett said. He was released after officers realized his identity, he said.

“Las Vegas police officers singled me out and pointed their guns at me for doing nothing more than simply being a black man in the wrong place at the wrong time,” Bennett said.

Bennett said he had retained a California civil rights attorney to investigate and may file a civil rights lawsuit.

Officials with the Seahawks could not be immediately reached for comment.

Bennett recently declined to stand for the national anthem before a game after the violent clashes in Charlottesville, Virginia, between white nationalists and counter-protesters, according to CNN.

Colin Kaepernick, a former quarterback for the San Francisco 49ers known for his activism, tweeted his support Wednesday: “This violation that happened against my Brother Michael Bennett is disgusting and unjust,” he wrote.