Seattle Seahawks defensive end Michael Bennett has made allegations about his treatment at the hands of the Las Vegas police department late last month.
Bennett, a Super Bowl champion and two-time Pro Bowler with Seattle, says he was left fearing for his life during an incident in the aftermath of Floyd Mayweather's win over Conor McGregor on August 26.
In an open letter posted on his Twitter account on Wednesday, Bennett said he was taking legal advice after officers used "unbearable" force and threatened his life "for no other reason than I am black".
Las Vegas Metropolitan Police Department responded with a short statement on Twitter read: "This case is under investigation. Reserve judgment. We will address this publicly."
On his way back to his hotel, Bennett claims, he heard "what sounded like gun shots" and took off running before being singled out by police officers for "doing nothing more than simply being a black man in the wrong place at the wrong time.
"A police officer order me to the ground," Bennett wrote. "As I laid on the ground, complying with his commands not to move, he placed his gun near my head and warned me that if I moved he would 'blow my head off'.
"Terrified and confused by what was taking place, a second officer came over and forcefully jammed his knee into my back making it difficult for me to breathe. They then clinched the handcuffs on my hands so tight that my fingers went numb.
"The officers' excessive use of force was unbearable. I felt helpless as I lay there on the ground handcuffed facing the real-life threat of being killed.
"All I could think of was 'I'm going to die for no other reason than I am black and my colour is somehow a threat'.
"My life flashed before my eyes as I thought of my girls. Would I ever play with them again? Or watch them have kids? Or be able to kiss my wife again and tell her I love her?"
Bennett says he was eventually released without explanation when police determined he was a famous NFL player rather than a "thug, criminal or ordinary black man".
Bennett is one of many NFL players who choose not to stand when the US national anthem is sung because in his words "standing up for justice is just simply the right thing to do".
He added: "The system failed me. I can only imagine what Eric Garner, Michael Brown, Trayvon Martin, Tamir Rice and Charleena Lyles felt."