Popular anger over the use of torture was a key grievance behind the mass uprising that toppled Mubarak in February. Activists see the death of Essam Atta, 23, at a Cairo hospital late Thursday as an indication that little has changed since then. Egyptian authorities denied allegations that the guards had a hand in Atta’s death.

A lawyer for Atta’s family, Malik Adly, said Atta had been arrested while watching a street fight in February, convicted of thuggery in a military trial in February and sentenced to two years in Cairo’s Tora prison. Late Thursday, a prison guard brought Atta to a Cairo hospital, where he was pronounced dead from “unknown poisoning,” Adly said.

Atta had told his family that prison guards tortured him by using tubes to inject water into his mouth and anus, Adly said. After his death, other prisoners called Atta’s family to tell them he had died during torture, according to Adly.

“We accuse the officers of the Tora prison of being behind the victim’s death,” Adly said. “We know that the Interior Ministry in Egypt is filthy, practices filthy policies and doesn’t give any importance to human life.”

Cairo’s Nadim Center for Victims of Torture also accused guards of killing Atta.

An Egyptian security official denied the allegations, saying prison medics found that Atta had taken drugs and was suffering from exhaustion. When his condition worsened, he was taken to the hospital where he died.

Atta was arrested in 2004 for drug dealing, and in 2010 for illegal weapon possession, the official said. The two-year sentence he was serving at the time of his death was for squatting in a residential apartment, the official said, speaking on condition of anonymity because he was not authorized to brief the media.

Some Egyptians drew parallels between Atta’s death and that of Khaled Said, a 28-year-old who was beaten to death by police officers in June 2010. Pictures of Said’s bloodied face, broken jaw and bruised body were widely circulated, and activists later used a Facebook page called “We are all Khaled Said” to help organize the anti-Mubarak uprising.

Many noted that Egyptian authorities had also portrayed Said as a drug dealer who died after choking on a packet of drugs he swallowed to hid it from police.

An independent forensic committee later found that the packet was forced into his mouth after his death, and two policemen were sentenced in the case to seven years in prison each earlier this week.

Within hours of Atta’s death, someone created a Facebook page called “We are all Essam Atta,” which contained photos of his dead body with white foam filling his mouth and gauze binding his head and hands.

The photos’ authenticity could not be independently verified.

Adly said Atta’s family has asked Egypt’s state prosecutor for a full investigation into Atta’s death.