The Nassau Criminal Courts Bar Association says there are holes in the 'Flush the Johns' prostitution sting cases from last year.

As News 12 Long Island has reported, Nassau District Attorney Kathleen Rice announced the arrest of 104 men after a sting operation by the Nassau Police Department. Defense attorneys say the lack of audio recordings of the phone calls in which the johns allegedly agreed to pay for sex make the cases flawed.

Attorney Brian Griffin, who represents five of the 104 defendants, says he has never been able to get a straight answer as to why there are no audio recordings of the alleged sex calls.

"They had the equipment to record conversations, so one would ask why the police did not capture evidence in a criminal case when they have the ability to do so," says Griffin.

Nassau police have not commented on why the audio is missing. The Nassau District Attorney's Office says the investigation is sound and that it's too early to judge all 104 cases.

So far, 13 men have pleaded guilty, two have been acquitted and six cases have been dismissed, according to a district attorney spokesman.