(07-25) 16:42 PDT SAN FRANCISCO -- A lieutenant from the San Francisco Sheriff's Department denied charges Wednesday that he pushed and punched a man he used to date during an argument in a fitness gym locker room.

Vincent Calvarese, 48, pleaded not guilty to misdemeanor charges of assault, battery and false imprisonment for the July 19 off-duty incident at Gold's Gym on Market Street. He was booked into jail and then released after posting $10,000 bail.

Calvarese - who lives in the city's Castro neighborhood and appeared the 2009 documentary about gay culture called "The Butch Factor" -dated the victim from January to March of this year, said Assistant District Attorney Ilana Jacobs.

Witnesses told police Calvarese confronted the victim at the gym and accused him of lying during their relationship. He allegedly told him, "I'm a captain, I can have you arrested."

Jacobs said Calvarese followed the victim into the locker room and began pushing and punching him. Bystanders tried to intervene, but Calvarese broke free and continued the assault.

Judith Odbert, his attorney, said her client "was assaulted first" and DNA evidence on a shirt confiscated during the investigation would prove that point. She refused to comment further outside court.

Judge Susan Breall ordered that Calvarese stay away from the victim and the gym where the attack took place. She ordered him to surrender all firearms.

Calvarese, who worked in the jails as part of the department's custody division, has been placed on administrative duty, said Susan Fahey, spokeswoman for the sheriff's department. Separate from the court proceedings, such cases are reviewed on a case-by-case basis to determine what disciplinary action the department might take, Fahey said.

Fahey would not comment on the allegations that Calvarese used his job to threaten the victim. But District Attorney George Gascón called the allegations "disturbing" and that the investigation is "an ongoing process."