The Egyptian government on Wednesday sought to distance the police from last weekend's shooting death of a female protester, saying a forensic examination showed she was killed by a type of projectile that is "absolutely" not used by security forces.

The case of 32-year-old Shaimaa el-Sabbagh, who died after birdshot fired by police hit her during a peaceful rally on Saturday in Cairo, has stirred withering criticism of the police force and its heavy-handed implementation of a law banning demonstrations without prior government approval.

A senior Interior Ministry official on Wednesday also dismissed as "inconsequential" video clips showing two masked, black-clad policemen pointing their rifles in el-Sabbagh's direction as gunshots rang out and a voice commanded "fire."

The official, Gamal Mukhtar, also hinted that the outlawed Islamist Muslim Brotherhood group might have fabricated graphic images and videos of el-Sabbagh, to incriminate the police.

"The images are absolutely inconsequential," said Mukhtar, who is also a brigadier-general in Egypt's highly militarized police force. "There is a brigade from the Brotherhood that is entirely dedicated to fabricating photos and videos that tell stories of police attacking citizens."

The police had no need to use force to disperse the small protest in which el-Sabbagh participated, Mukhtar told reporters.

"Was there a need for police to open fire? Do you think security forces could not handle that number so it opened fire? If we wanted to disperse a protest of that size, we would just ask the protesters to leave," he said.

Mukhtar did not explain why police used tear gas to disperse the protest, as was stated by the country's top prosecutor.

The rally had gathered about 40 participants who intended to lay wreaths at the nearby Tahrir Square, the epicenter of Egypt's 2011 revolution that ousted autocrat Hosni Mubarak, in memory of protesters killed during that 18-day uprising.

El-Sabbagh's case has attracted much attention, in large part because of graphic video and images widely spread on social media networks showing her colleagues carrying her bloodied body away from the scene of the clash. She later died in a hospital she was taken to.