An Egyptian Coptic Christian arrested on suspicion of posting online an anti-Islam film that ignited Muslim protests around the world should be freed immediately, Amnesty International said on Tuesday.
Computer science graduate Alber Saber was detained by police in Cairo last month after his neighbours accused him of uploading sections of the film "Innocence of Muslims" and of making another movie that mocks all religions.
The case has raised concerns over freedom of expression under Islamist President Mohamed Mursi, who came to power in free elections earlier this year after the 2011 popular uprising that toppled autocrat Hosni Mubarak.
Saber is in jail and due to attend his second trial session for blasphemy on Wednesday. If found guilty, the 27-year-old could be jailed for up to six years, according to a report by rights group Amnesty, which also said Saber had told his lawyers he had been beaten in custody.
"Alber Saber Ayad is a prisoner of conscience, detained solely for peacefully exercising his right to freedom of expression and should be released immediately," Hassiba Hadj Sahraoui, deputy director of Amnesty's Middle East and North Africa Programme, said in a statement.
"Criticism of religions and other beliefs and ideas is a vital component of the right to freedom of expression. Laws - such as blasphemy laws - that criminalise such criticism violate human rights," Sahraoui added.
The report said Saber had told his lawyers that a police officer in prison had incited other detainees to attack him.
"The detainees beat Alber Saber Ayad and cut him with a razor blade along his neck. He was then taken to another room where he was beaten by 20 prisoners and forced to remain standing all night," Amnesty said, reporting what his lawyers had said.
According to Amnesty's report, Saber's lawyers fear for the safety of his family who had reported that they had been threatened and been forced to leave their home.
Local rights groups had previously voiced similar concerns about Saber and called for his release.
The anti-Islam film, made in California, portrayed the Prophet Mohammad as a womaniser, thug and child molester. Crowds stormed U.S. embassies around the Arab world in protest at it. In Libya, the U.S. ambassador was killed by Islamist militants.