The Egyptian prosecution said on Sunday that Hamada Saber changed his testimony and accused the security forces of firing at him and assaulting him.
Local satellite channels and international media had aired footage of Saber being attacked, dragged and stripped naked by riot police at a Friday protest by the presidential palace.
Saber, 48, had refused at first to bring accusations against the police.
Saber and his wife appeared on national television at a police hospital a day after the attack and claimed that protesters, not riot police, assaulted and stripped him in search for his money.
His testimony changed after the prosecution questioned him over the video.
As suspicions that the man and his wife were threatened to falsely testify started rising, Saber's family members, including his daughter, started coming forward to the media and confirming that he was in fact threatened to not blame the police for the attacks.
The video sparked fury over the weekend especially among opposition forces who condemned the use of violence against protesters and an apologetic reaction from the interior ministry as well as a condemnation from the presidency.