Jakarta – Only a week before representatives of the Indonesian government and the separatist Free Aceh Movement (GAM) are to meet for peace talks in Helsinki, an Indonesian court on Wednesday sentenced a senior GAM leader to life in prison for treason and illegal possession of weapons.

The sentence against Teungku Muhammad Arif, 76, a civilian leader of GAM in Aceh Pidie Regency, was similar to the term sought by government prosecutors two weeks ago.

Presiding Judge Edian Satria of the Aceh Pidie District Court told Kyodo News a couple hours after the verdict was read out that the defendant had violated the country's 1951 Emergency Law by illegally possessing weapons and committing treason against the legitimate government.

According to Satria, Arif, who was appointed by GAM leader-in-exile Hasan Tiro in 2002, had been involved in a series of kidnappings and killings of civilians in Aceh and in efforts to separate the oil-rich province from Jakarta The ailing Tiro is in exile in Stockholm.

During the court proceedings, the defendant also confessed that in 1954 he led a group of rebels that wanted to establish an independent Islamic state and in 1976, along with Tiro, he declared the Free Aceh state.

Arif, who was a civil servant at the Ministry of Religions Affairs from 1980 to 1981, was arrested by police on Oct. 2 last year in a hiding place in Geulumpang Baro in Aceh Pidie Regency.

The verdict came just a few hours before the state of civil emergency in Aceh, which has been imposed since May 19 last year, ends at midnight Wednesday.

In 2003, then President Megawati Sukarnoputri launched a major military assault to crush GAM, putting the province under martial law – later downgraded to a state of civil emergency in May 2004 – and limiting the movement of foreign reporters and aid workers.

But after the Dec. 26 earthquake and tsunamis devastated Aceh, the government allowed foreign aid workers, troops and journalists to enter the province and the disaster led the two adversaries to resume peace negotiations.

GAM has been waging a guerrilla war since 1976, seeking independence for Aceh. The rebels accuse the central government of human rights violations in Aceh and of squandering the province's natural resources while leaving the Acehnese in poverty. Thousands of people, mostly civilians, have been killed in the conflict.