Cairo's criminal court on Tuesday renewed the detention of Al-Wasat Party's deputy president, Essam Sultan, on charges of inciting violence at the pro-Muslim Brotherhood Rabaa Al-Adaweya protest camp a year ago.
The court extended Sultan's detention for an additional 45 days.
Sultan, who was arrested in late July 2013, is also accused of calling on Islamists to torch state institutions in the east Cairo district of Nasr City, where the camp was held.
Sultan's party was one of the most prominent members of the Brotherhood-led National Alliance to Support Legitimacy (NASL).
In an unexpected turn of events, the Al-Wasat Party withdrew from the NASL last week, citing the need to be part of a wider political alliance.
The Al-Wasat Party was founded in 1989 as a breakaway splinter of the Brotherhood. It gained official recognition from the state as a party in the aftermath of the 2011 uprising.