KANSAS CITY, Kan. (AP) — Federal prosecutors say the government isn’t required to pay for an expert to investigate whether recordings inside a private prison violated inmates’ constitutional rights.

Attorneys say some of their meetings and phone calls with clients at the Corrections Corp. of America prison in Leavenworth, Kansas, have been recorded in violation of the inmates’ Sixth Amendment right to a fair trial.

U.S. District Judge Julie Robinson has appointed Ohio attorney David Cohen as special master to look into possible violations of attorney-client privilege. He will be paid $500 an hour to identify confidential information in possibly hundreds of hours of recordings, and Robinson ordered the Department of Justice to pay him.

Prosecutors argue in a motion filed Thursday that Robinson isn’t authorized to force the government to pay for Cohen’s services.