A right-wing internet radio host has been sentenced to 33 months in prison for threatening the lives of three Chicago federal appeals court judges after they upheld a local gun control law.

Harold Turner, 48, was convicted by a Brooklyn federal court jury in August following two mistrials.

He had been arrested in June 2009 and charged with one count of threatening to assault or murder the three judges.

Turner used his radio broadcasts to target Judges Frank Easterbrook, Richard Posner and William Bauer of the US Court of Appeals for the 7th Circuit in Chicago, who had upheld a local handgun law.

He said they had acted in "a manner so sleazy and cunning as to deserve the ultimate punishment."

He called for their murder and published their photographs and work addresses online.

"Turner's harsh words about these targeted judges, launched by Turner to an audience containing members of violent and extreme groups, prompted the United States Marshals Service to assign protective details to many of the judges," court documents said.

Turner, of North Bergen , New Jersey, worked as an FBI source between 2003 and 2007, US prosecutors said, due to his "popularity with and access to white supremacist groups."

-Reuters