A pedestrian walks past a line of New York Police Department (NYPD) cars parked at Times Square in New York, US, October 18, 2011. REUTERS/Gary Hershorn/Files

NEW YORK: Authorities seeking illegally acquired antique artworks have searched the apartment and office of a prominent New York billionaire and philanthropist, prosecutors said.

As many as nine pieces were reportedly seized. The 77-year-old Michael Steinhardt ? who was the target of the inquiry ? made his fortune as a hedge-fund manager.

A spokesman for Manhattan district attorney Cyrus Vance Jr. would neither confirm nor deny the seizures Friday but did confirm the searches. Vance has been active for years in trying to repatriate stolen artworks.

Steinhardt is a well-known collector of Greek antiquities and even has a gallery named after him and wife Judy in the Metropolitan Museum, not far from their Fifth Avenue apartment. Steinhardt told The New York Times he had no comment on the matter "for now."

Copies of search warrants provided to AFP, and signed by a New York judge on January 3, indicated that investigators were seeking about a dozen antiques from Greece and Italy, acquired between 1996 and 2011 for sums ranging from $25,000 to $380,000.

´Thousands´ of pieces returned

The latter sum was spent in 2006 to acquire an 18-inch tall (45-centimetre) white oil vessel that depicts the figures of a woman and a young boy in a funerary scene dating from around 420 BC.

A spokesman for the prosecutor´s office would not say whether Steinhardt might face any charges, but the search warrants list criminal possession of stolen property as a potential violation.

In recent years, Vance´s office has made it a priority to track stolen works -- seizing some from museums, private collections or auction houses -- and return them to their rightful owners, including in Lebanon, Pakistan and Italy.

So far, no charges have been brought against anyone for possessing the disputed works -- which sometimes pass through several hands before reaching owners in New York, the Times said.

Thus, on December 15 three antiques were returned to Lebanon. They included a Greek bull´s head statue that had been exhibited at the "Met." Its estimated value: $1.2 million. Vance´s office said it had been stolen during Lebanon´s civil war.

Vance said at the time that his office had, since 2012, tracked down several thousand antique pieces with a total value of more than $150 million.