HOBOKEN -- The bronze head of Ol' Blue Eyes has disappeared, and the Hoboken city clerk is not happy about it.

At least two weeks ago, someone managed to slice off a thin bronze portrait of Frank Sinatra that adorned a plaque at Frank Sinatra Park on the Hoboken waterfront, City Clerk James Farina said Tuesday.

Police are investigating.

Farina said that during one of his morning walks for exercise approximately two weeks ago, he noticed that the Hoboken-born singer's portrait had been carved off the plaque.

"I called the chief of police," Farina said. "I know he's a Frank Sinatra fan. I said, 'I need an investigation.' He said, 'For what?' I said, 'Sinatra's head is missing from the plaque.' He said, 'Where is it, in your living room?' "

Farina said that he has been in contact with Hoboken-based architect Dean Marchetto, who designed the park pavilion, to "give me the information about where they ordered the plaque from and see if we can get a duplicate of that portrait."

Over the years, other Sinatra items in town have gone missing, including streets signs for Sinatra Drive, which snakes along the waterfront.

Farina said that if the purloined portrait is not returned, he will find a way to make sure the city gets a new one.