Egypt's prosecutor general appealed on Wednesday against the outcome of the trial of Hosni Mubarak and several of his senior officials over deaths in the uprising that unseated the veteran strongman.
The prosecutor called for the June 2 verdicts to be annulled and for a new trial to be held.
It was not immediately clear on what grounds the appeal was made.
Prosecutor General Abdel Meguid Mahmud said a day after Mubarak and former interior minister Habib al-Adly were sentenced to life in prison and six senior police officials acquitted, that he would lodge an appeal.
The verdicts, particularly against the police officials, set off a wave of protests by people who said they were too lenient.
Judge Ahmed Refaat convicted Mubarak and Adly for their roles in the deaths of more than 800 protesters during the revolt that ousted them in February last year but failed to punish any of those who actually conducted the killings.
Corruption charges against Mubarak's sons, Alaa and Gamal, were also dropped because of the expiry of a statute of limitations, and the ex-president was acquitted in one of the graft cases.
But Alaa and Gamal remain in custody because they are awaiting trial in another case.
At the time, a senior member of Mubarak's defence team told AFP the 84-year-old would himself appeal the verdict.