A lawyer filed a complaint with the attorney general on Saturday, accusing a police officer in Marg prison of assaulting imprisoned blogger Maikel Nabil.
"Nabil's brother reported this to me after he visited him in jail," the lawyer, Amir Salem, said.
The next day, the attorney general dispatched a prosecutor, who met with Nabil alone and took his testimony.
Nabil, 25, was arrested in March and jailed by a military court on charges of defaming the army. In December, his prison term was reduced from three to two years after the court reviewed his case.
He has already served about eight months of his sentence.
The prosecutor said Nabil confirmed he was assaulted by the officer and another guard, and that they pledged not to assault him again until he is moved to Tora prison.
"We asked them to move Nabil to the Tora prison hospital or any other public hospital because of his poor health condition after he went on hunger strike for a long time and lost weight," Salem said.
“Nabil does not receive proper medical care in prison,” he said, adding that the prison hospital is poorly equipped. “I can't even call it a hospital.”