Lawyer for man who accused Christian girl of burning Qur'an raises spectre of vigilante act if Rimsha Masih is not convicted

A lawyer representing the man who accused a Pakistani Christian girl of blasphemy has said that if she is not convicted, Muslims could "take the law into their own hands".

Rao Abdur Raheem cited the example of Mumtaz Qadri, the man who last year shot dead a politician who had called for reform of the much-abused blasphemy law.

The apparent hijacking of the case against Rimsha Masih by organised extremists, including lawyers, could further complicate a bitterly contentious case.

The lawyer's comments are likely to further complicate a bitterly contentious case that has caused an international outcry and embarrassed the Pakistani government. It could intimidate the court and would put her life at further risk even if she is freed.

The girl, Rimsha Masih, from Mehrabadi, Islamabad, whose family says she is 11, was arrested this month and charged with desecrating the Qur'an after a neighbour, Malik Hammad, claimed that he saw her with burnt pages of the holy text in a bag she was carrying.

Her family had hoped that she would be granted bail on Thursday after a medical report this week found that she was a minor – thus eligible for bail – and had learning difficulties. But those hopes were dashed when Raheem challenged the report and the hearing was postponed.

According to Raheem, the medical report on Masih was illegal, as it followed the orders of a civil servant and not the court, and went beyond its remit of determining her age. He accused the government of supporting her and manipulating court proceedings. Speaking outside the Islamabad court after the hearing, Raheem said: "There are many Mumtaz Qadris in this country … This [medical] report has been managed by the state, state agencies and the accused."

The case has caused an international outcry. Later, sitting in his office beneath a large poster of Qadri, Raheem told the Guardian: "If the court is not allowed to do its work, because the state is helping the accused, then the public has no other option except to take the law into their own hands."

There is however a glimmer of hope. In this case, for the first time in the case hardline Islamic clerics have cautioned against presuming the guilt of Rimsha Masih. Last night one of Pakistan's most radical mullahs, Ahmed Ludhianvi, head of the banned Sipah-e-Sahaba, which is blamed for hundreds of sectarian killings, told the Guardian: "There should be a thorough investigation. If she [Masih] didn't do it, she should be freed. If she is mentally disturbed, scholars should consider what should be done. Islam does not allow anyone to be punished instantaneously."

Last year, many lawyers rallied around Qadri, who killed Punjab governor Salman Taseer, showering him with rose petals when he appeared in court.

Raheem said he had taken on the case for free because he was convinced that Masih should be punished. "This girl is guilty. If the state overrides the court, then God will get a person to do the job," he said.

However, it seems unclear why the accuser suspected Masih and how he saw inside the bag that she was apparently carrying. It is also unclear whether any burnt pages were actually from the Qur'an.

Following Raheem's objections to the medical report, the court has asked the authorities for clarification and will hear the case again on Saturday, when bail for the girl could again be considered.

Blasphemy allegations are often made on the flimsiest of evidence but enraged mobs pressure the police into registering cases. In court, the alleged act of blasphemy cannot even be repeated, as that would be an act of blasphemy in itself, so verdicts are reached in the absence of the main piece of evidence.

Earlier this year, a mentally disturbed Muslim man in Bahawalpur, a city in the middle of the country, was accused of blasphemy and arrested. After a crowd of up to 2,000 stormed the police station and dragged him out, he was beaten and burned alive. In 2009, a mob attacked an area where Christians lived in Gojra, a town in Punjab province, burning at least eight people to death.

The fate of the Christians at Gojra hangs heavily over Masih's own community. They fled en masse after Rimsha Masih was taken away by police from her home. Now, two weeks on, many of the Christians have trickled back, but they remain terrified.

One Christian, Arif Masih, returned to his house in Mehrabadi after nine days to find it looted. "People are so afraid, they cannot sleep at night," he said. "We just want to leave, we want to be given somewhere else to live," said Masih.

• This article was amended on 31 August 2012 to correct editing mistakes throughout.