Morsi's defense team said they and Morsi's family members headed to the prison Thursday after obtaining a permit from the general prosecution to visit the ousted president, but that when they arrived at the prison, they were not allowed to see him, Ahram Online reported.
Osama Morsi, the former president's son, alleged that his father had been "kidnapped."
"The president is surely not at Borg al-Arab Prison," Osama Morsi posted on Facebook.
Lawyers for Mohamed Morsi said they would attempt to visit him again next week.
Morsi is being detained at Borg al-Arab Prison pending an investigation into a 2012 incident at the Presidential Palace in Cairo, in which he is accused of inciting the killing of protesters.