Apparently prompted by a sign in a City Hall art display reading "Show me yours," a man yesterday exposed himself to exhibit visitors and fled before police arrived on the scene.

The exhibit, which opened on Thursday and focuses on issues of sexuality and gender identification, had already been a subject of controversy around the city.

"It's plain, simple, vulgar," said city council member William H. Walsh.

Walsh, who is presently awaiting sentencing for his conviction last spring on 41 counts of bank fraud and conspiracy, removed two dildos and a photograph of a penis from the exhibit on Wednesday and took them home.

Cambridge City Manager Robert W. Healy then contacted Walsh and reclaimed the items.

But the offending objects were back in the exhibit as of yesterday afternoon, Walsh said.

"I don't know what he did with it," Walsh said of Healy, "but it's back over there."

Temporary walls were installed around the exhibit Thursday, along with a disclaimer informing the public that the artwork was chosen by a "jury of professional artists" and not the employees of City Hall.

"[The jury] must have been blind when they chose it," Walsh said.

Despite the cautionary measures, a City Hall employee has submitted a complaint asking "to have the exhibit shut down," said Margot P. Kosberg, executive director of the Cambridge Human Rights Commission.

Any action on the complaint is "pending," Kosberg said.

The exhibit is presently on the second floor in the 57 Inman Street annex of the Cambridge City Hall.