The U.S. military is investigating a Guantanamo Bay prisoner's interview with a Middle East television network.

The U.S. does not permit journalists to interview prisoners. Officials say that would violate the Geneva Conventions.

Navy Lt. Cmdr. Brook DeWalt tells The Associated Press that Mohammed el Gharani apparently used a weekly family call to speak to a journalist from Al-Jazeera and allege that guards abused him.

DeWalt says El Gharani is among relatively few prisoners who can make weekly calls.

The U.S. makes sure numbers called by prisoners are really those of family members. But DeWalt said Wednesday there is nothing the U.S. can do to guarantee the person on the other end of the line is in fact a relative.