CAIRO (AP) — Egypt’s top prosecutor imposed a media gag order Thursday on the case of a female protester killed during a peaceful demonstration last month.

Rights groups and political factions accuse the police of killing 32-year-old Shaimaa el-Sabbagh, pointing to widely circulated footage that showed two masked, black-clad policemen pointing their rifles in her direction as gunshots rang out and a voice commanded “fire.”

She was killed on Jan. 24, the eve of the fourth anniversary of the uprising that ousted longtime autocrat Hosni Mubarak.

The police sought to distance themselves from the killing, which revived longstanding charges that they routinely use excessive and lethal force.

On Thursday, a statement from the prosecutor general’s office said the gag order will remain until the investigation is completed.

The statement said “inaccurate and contradictory” media reports about the investigation into el-Sabbagh’s killing could “negatively impact” the probe.

Various rights groups have complained that police officials are almost never prosecuted in Egypt, propagating a culture of impunity. Over a hundred policemen were acquitted in trials stemming from the killing of demonstrators during the protests against Mubarak in 2011.

Since then, no police officer or security official has been charged over the killing of protesters, despite a wider, more violent crackdown on dissent.