From behind the bars of his prison cell, as he awaits his trial for anti-state activities, mild-mannered Aceh independence activist Muhammad Nazar is still a man Jakarta fears.

Even while incarcerated, Nazar is gathering evidence against the Indonesian authorities he and his colleagues regard as an occupation force. This time, however, the material is coming from his fellow inmates. Nazar is also planning a new campaign – one based on the evidence he collects.

Nearly all of his fellow inmates were tortured by police, he says. Among them were suspected members of the rebel Free Aceh Movement, but others faced ordinary crimes. Nazar, 27, has used his forced leisure time to collect statements from them. "The majority of them were tortured by police. Maybe if we are free we want to campaign about the brutal legal process here," he said.

Nazar does not claim to have been physically tortured himself, but came close during the time he was held in a cell at provincial police headquarters. According to him he had to endure miserable conditions after his arrest in November, was constantly watched by police intelligence officers and received death threats. He was well aware of torture within the building. "I heard their cries."

Now, as his trial approaches, he has been moved to an ordinary jail, where most of his jailers are fellow Acehnese and he can talk more freely to visitors. With a scraggy beard and thin frame, he looks little match for the Indonesian legal machine.

His defence team says Nazar is simply a political prisoner and his arrest merely a bid to silence the independence movement. He is the co-ordinator of Sira, a student-led lobby group campaigning for a peaceful referendum on independence for Aceh. The group has in the past organised large demonstrations calling for the Sumatran province to be given the same choice on its future as East Timor. The organisation's influence has been enormous and authorities have at times resorted to using controversial laws to incarcerate members.

The accusations against Nazar relate to a banner put up in August last year. They are based on three articles in the criminal code dating from Dutch colonial days. In essence, he is accused of causing hatred to the state. These laws were often used by former president Suharto to jail his political opponents.

Nazar's is the first case involving these laws since Suharto fell in 1998. Many legal experts fear the move augurs ill for Indonesian justice and the laws should instead be repealed. Nazar's lawyers are pressing for a quick trial and are optimistic they can get him acquitted.

In the 1990s, wide-scale torture and killings by the Indonesian military set the stage for the current push for independence in Aceh. However, human rights activists say the situation now is as bad, if not worse. It is not helped by the presence of large numbers of troops and police from outside the province, who generally do not speak the language and feel under constant threat from the rebels.

In the past the police were regarded as considerably less brutal than the military, but now that they are technically in control, that has changed.

Police, however, seem to realise that they could have a lot to lose by prosecuting Nazar after they seized notes he had made – detailing prison activities.