Photo of Ahmed Arafa circulated on social networking sites.
A court in Cairo has sentenced a leading Salafist to life imprisonment for possession of unlicensed weapons.
The "life" sentence entails 25 years in prison according to Egyptian law.
Ahmed Arafa of the Hazemoon movement was arrested in December 2012 after a machine gun and ammunition were found in his apartment.
The search came after he was accused of involvement in attacks on the liberal Wafd Party headquarters earlier that month
Arafa was sentenced to life imprisonment in absentia in May but a court ordered a retrial after he appealed the ruling.
A Wafd party secretary had filed a report accusing supporters of former Salafist presidential hopeful Hazem Salah Abu-Ismail – known as 'Hazemoon' – of attacking the party offices, setting it on fire and assaulting police and party personnel.
Arafa's lawyer said the allegations were trumped up and his client had the weapons for self-defence.