An alleged acting crime boss and 19 other members and associates of the Genovese (search) organized crime family were arrested Thursday on extortion, loansharking and other charges.

The defendants include longtime capo Matthew "Matty the Horse" Ianniello (search), who allegedly became one of the family's acting bosses after Vincent "The Chin" Gigante was convicted, authorities said.

Ianniello and the other defendants awaited arraignment in federal court Thursday with additional charges of conspiracy, obstruction of justice, extortion and influencing a union official. His attorney, Jay Goldberg, denied his client was an acting boss, and predicted he would be cleared of the charges.

An indictment alleges that under Ianniello's leadership, the mob family infiltrated a local union and extorted payments from a medical center that rented office space from it.

Ianniello's brother Bobby was the former owner of Umbertos Clam House (search), the infamous Little Italy restaurant where a hit man gunned down flashy mobster "Crazy Joey" Gallo on April 7, 1972.

The slaying made Umbertos a must-see spot for tourists who scanned its woodwork and kitchen door for leftover bullet holes.

The arrests came a day after Peter Gotti, the brother of the notorious mob boss John Gotti, was sentenced to 25 years in prison for ordering a failed hit on Mafia turncoat Salvatore "Sammy the Bull" Gravano. The judge said Peter Gotti was a leader of the Gambino crime family.

John Gotti's son, John A. "Junior" Gotti, goes on trial next month on fraud, extortion and kidnapping charges, but prosecutors on Wednesday dropped another charge of murder conspiracy.