Egypt's chief prosecutor has referred a police officer to trial for the killing of a female protester during a peaceful demonstration.

The death of 32-year old Shaimaa el-Sabbagh, a mother of a young boy, in January caused intense public controversy; her shooting was caught on camera and widely shared online. Authorities initially denied police were behind her death.

The uproar prompted Egypt's President Abdel-Fattah el-Sissi to urge an investigation but he hinted that individual mistakes should not be used to undermine public confidence in the police force.

Prosecutor Hisham Barakat on Tuesday charged a police officer with involuntary manslaughter, a charge punishable by up to seven years. No trial date has been set.

The majority of the hundreds of policemen tried for killing protesters during Egypt's 2011 revolution were acquitted.