CAIRO - A group of independent doctors, who performed an autopsy over a prisoner killed Thursday in what his family and human rights activists call yet another case of torture inside Egypt's prison cells, said that they found no bruises in the prisoner's body, but indicated that he swallowed the length of two human fingers of hashish and another substance they could not identify. The body of Essam Atta, 24, was sent to hospital on Thursday, but his relatives alleged that his jailers tortured him for attempting to bring a cell phone into his prison cell and used hoses to force huge amounts of water and soap into his body, but this led to his death. A few hours after it was admitted into a Cairo morgue on Friday, Atta's body was taken by hundreds of activists who wrapped it in the Egyptian flag, carried it over their shoulders, and marched to Tahrir Square, the epicenter of revolutionary action since January. The activists called for an investigation into Atta's case, linking it to other cases of police torture, the latest of which being of a blogger from the coastal city of Alexandria who was beaten to death by policemen who were finally sentenced to seven years in prison last week. Egypt has been notorious for torture inside police stations and prisons, a fact that does not seem to have changed a lot after a popular uprising threw out Hosni Mubarak who ruled this country for the past 30 years, rights activists say. "We are given a very bad treatment inside the prison," said an unidentified inmate in a phone interview with private Al Nahar TV. "A cellmate has recently been beaten in a way that caused major injuries to his face," the inmate added. Mona Youssef, a blogger and an anti-torture activist, said torture was systematic inside the nation's prisons. She related the story of a prisoner who underwent torture, but even got a harsher dose of torture when his mother reported his case to the authorities. "I understand why people might fall silent when a relative undergoes torture in police stations or prison cells," Youssef said. "If these cases are reported, the prisoners might be subject to yet more torture," she added. Atta's case, however, might be different, according to the Al Tahrir Doctors, a group of independent doctors who examined Atta's body yesterday. The doctors say they watched the autopsy carried out over Atta's body and that the State-commissioned forensic doctors who performed the autopsy did their work both "skillfully" and "thoroughly". "There were no bruises in Atta's body, except for a superficial bruise on the right hand side of the body," the doctors said in a statement. "There is not either skull injury or bleeding in the brain," the doctors added in a statement. Atta was convicted of thuggery and sentenced to two years in prison by a military court in February, according to a statement from the Interior Ministry on Friday. He had been charged with drug trafficking in 2004 and carrying an unlicensed weapon in 2010, the statement said.