The 10 federal policemen assigned to protect prosecutor Alberto Nisman, found dead hours before he was set to testify on allegations that President Cristina shielded Iranian spies, are being questioned about their actions the day Nisman was found dead.

The policemen, along with two supervisors, have been suspended while an internal investigation takes place, a person close to the investigation told The Associated Press on Friday on the condition of anonymity. The 51-year-old prosecutor was found Sunday night slumped in the bathroom of with a bullet wound in his head.