NEW YORK (AP) — An attorney for Kristaps Porzingis acknowledges that a woman has accused the NBA star of rape, but says the Dallas Mavericks forward “unequivocally” denies the allegation.

Lawyer Roland Riopelle said Saturday that the claim against the player was part of an extortion attempt that is being investigated by the FBI.

NYPD Chief of Detectives Dermot Shea said on Monday that the department has an ongoing probe into the allegation. The chief declined to give further details.

Citing unidentified law enforcement officials, the New York Post and other news organizations reported earlier that a woman went to police Thursday and said Porzingis raped her in his Manhattan apartment last year while he was playing for the Knicks.

Riopelle says Porzingis reported to federal law enforcement in December that the accuser was making “extortionate demands.”

The attorney says the NBA was also notified.

Porzingis, a 23-year-old native of Latvia, was traded to the Mavericks in January.