Hundreds of Egyptian activists, lawyers and other admirers are gathering to pay a final farewell to one of the country's leading civil rights advocates, a lawyer who represented Islamists, atheists and homosexuals and worked to hold Egypt's decades-old police state accountable for torture and abuse.

The funeral of 63-year-old Ahmed Seif is being held in a Cairo mosque on Thursday, a day after he passed away following complications from heart surgery.

Seif's death comes at a time when several of the leading activists behind the 2011 uprising that toppled President Hosni Mubarak, including two of the deceased lawyer's three children, are in jail for violating a controversial protest law.