Video: San Diego Businesswoman Dianne York Becomes Mayor Bob Filner's 18th Accuser

Another woman has come forward to accuse San Diego Mayor Bob Filner of sexual harassment.

Businesswoman Dianne York told CNN that Filner put his hands on her buttocks during a photo opportunity that followed a meeting three months ago. York said there were witnesses to what happened. She said both her advisers and Filner's were in the room at the time.

York is the 18th woman to accuse Filner of improper conduct. One woman said Filner gave her "tush a pat." Another said he "put me in what I guess now is the famous headlock" and tried "to kiss me on the lips and I'd have to squirm to get away."

Filner's former communication director, Irene McCormack Jackson, quit her job and sued the mayor in July, saying he subjected women to "crude and disgusting" comments and inappropriate touching.

Filner recently acknowledged inappropriate behavior, but has steadfastly resisted efforts to force him out of office. He has said publicly that his misconduct was not enough to force him out of office, and has insisted he will be vindicated by "a full presentation of the facts."

The city has changed the locks to the mayor's office, and mediation talks that could effectively end his tenure in office are continuing, City Attorney Jan Goldsmith said Tuesday.

The talks come on the heels of Filner's intensive two-week behavioral therapy, which was apparently aimed at ending his allegedly backward ways of treating women in the workplace.

The mayor began the voluntary program July 29, but his attorney, James Payne, said he was able to complete it August 10, and he was expected to continue with outpatient treatment.