The high-profile conviction of a Brooklyn rabbi on sex abuse charges has been thrown into doubt amid allegations of witness tampering and blackmail.

Baruch Lebovits, 60, was jailed for up to 32 years after being convicted by a Brooklyn court last year of sexually abusing a teenage boy.

This week, the Brooklyn District Attorney Charles Hynes arrested another Brooklyn rabbi, Simon Kellner, on charges that he paid a child $10,000 to testify falsely that he had been abused by Lebovits.

Kellner, 49, was also charged with attempting to blackmail the Lebovits family for $400,000 or he would bring more boys forward with abuse claims.

District Attorney Hynes said at a press conference this week that he remained confident Lebovits's conviction would stand.

Lebovits's defence team, which now includes Alan Dershowitz, moved swiftly to have Lebovits released pending an appeal.

On Wednesday, a judge set bail at $250,000 cash and ordered Lebovits to remain under house arrest. It is not known if he has been released.

Kellner, meanwhile, faces up to 21 years in jail. He denies all charges.