ATLANTIC CITY, N.J. — A defendant in a New Jersey sex video-blackmail trial says he thought he was helping the FBI when he helped lure an Atlantic City councilman to a tryst with a prostitute.

Floyd Tally is one of three men charged with setting up the videotaped sex sting of Councilman Eugene Robinson [pictured].

Tally testified Tuesday that the confessed mastermind of the plot, former Council President Craig Callaway, told him he was cooperating with the FBI in an investigation of an official using his city vehicle to pick up prostitutes.

Tally said he agreed to help “catch him in the act,” but claims he did not know it would be recorded.

In previous court hearings, FBI agents offered no evidence of an investigation into Robinson.