NEW YORK – The acting boss of the Gambino family and at least 30 other mob figures were arrested after an undercover FBI agent posing as a wiseguy infiltrated the Mafia with an act so convincing he was considered for membership, authorities said Wednesday.

Among those arrested was Arnold “Zeke” Squitieri, who allegedly took over as acting Gambino boss after Peter Gotti was convicted last year. Also facing racketeering charges is reputed underboss Anthony “The Genius” Megale.

Prosecutors said Squitieri, Megale and other defendants made millions of dollars through extortion, loansharking, illegal gambling and other crimes during the past decade. Some of the crimes – which included the shakedown of a radio station and a beating at Bloomingdale’s – were plotted at a nursing home, court papers said.

Pasquale D’Amuro, head of the FBI’s New York office, said the undercover agent made hundreds of secret recordings revealing the family’s inner workings.

It was a feat not seen since FBI agent Joe Pistone penetrated the Bonanno family 25 years ago under the alias Donnie Brasco, he said. Like Brasco, the agent “was told by a high-ranking member of the crime family that he would be proposed for induction,” D’Amuro said.

“Had we left him out on the street much longer, the Gambino family ranks would actually have increased by one,” D’Amuro said.

The unidentified agent “risked his life as a mole for the better part of two years,” said U.S. Attorney David Kelley.

Squitieri awaited arraignment. A call to his attorney was not immediately returned. Megale, in jail in Connecticut, denies he is underboss, said his attorney, Stephan S. Seegar. Both men could get up to 20 years in prison if convicted.

The radio station – which is in the city but not identified in court papers – was among several businesses allegedly targeted for extortion. Authorities said the station was forced to run advertisements and promotions for Gambino-controlled businesses.

Authorities also allege that two of the defendants attacked a third mobster earlier this year in the housewares department at a Bloomingdale’s in White Plains, N.Y. The victim was severely beaten with a candlestick.

Some of the defendants allegedly tried to avoid scrutiny by holding meetings at the bedside of the comatose son of a mobster at a nursing home in New Rochelle, N.Y.