Miami: The NFL confirmed on Friday it is investigating an allegation of sexual assault against Tampa Bay Buccaneers quarterback Jameis Winston after a female Uber driver complained of being groped by the star last year.

BuzzFeed News reported that the driver had alleged Winston grabbed her during a ride in Scottsdale, Arizona in March 2016. Winston has denied the allegation.

Winston is now being probed by the NFL’s special counsel for investigations, Lisa Friel, who had written to the quarterback’s accuser. “The League has been informed that you may have been the victim of such a violation perpetrated by Tampa Bay Buccaneers player Jameis Winston,” Friel wrote in the letter.