An after-school tennis coach has been accused of sexually assaulting multiple young girls in the Bronx — and the cops are asking the public what they know about the alleged sexual predator.

Gerardo Gutierrez was arrested Feb. 15 on a half-dozen underage sex abuse charges, but those charges swelled to 73 counts after a grand jury indicted the 30-year-old the next month, according to cops and court records.

Gutierrez, who was a coach with the New York Junior Tennis League afterschool program, allegedly sexually abused at least three girls under age 12 inside PS 100X between November 2019 and July 2021, according to police.

The Bronx District Attorney’s Office later accused the Bronx man of predatory sexual assault against a child in the more than six-dozen-count indictment that was handed up in mid-March, court records show.

Bronx Judge Steven Barrett set bail at $150,000 when Gutierrez appeared on the indictment on March 18, records show.

Gutierrez remains in lockup at Vernon C. Bain Correctional Center, jail records show.

Cops released the man’s photo Friday and asked the public to come forward with any information about the accusations.