Jakarta – An Indonesian court on Monday sentenced the former boss of flagship carrier Garuda to one year in jail for assisting in the murder of a prominent rights activist, a judge said.

The high-profile activist Munir Said Thalib died aged 38 as he travelled from Jakarta to Amsterdam in 2004, poisoned by a Garuda pilot accused of links to Indonesia's powerful intelligence agency.

"The defendant, Indra Setiawan, has been proven, legally and convincingly, of having been guilty of the crime of assisting a premeditated murder," judge Heru Pramono said, reading the verdict at the Central Jakarta district court.

"The action of the defendant damaged the image of Garuda Indonesia as the country's national airline," said the judge, citing one of the factors in the ruling against the defendant.

Pramono said that the Supreme Court's ruling last month that saw an off-duty Garuda pilot, Pollycarpus Priyanto, sentenced to 20 years in prison for murdering Munir was also taken into consideration in formulating the verdict.

Setiawan had been charged with falsifying documents that had allowed Priyanto to travel on Munir's flight.

Pramono said that the defendant's polite stance and respect of the court helped in his favour. Prosecutors had asked that he be sentenced to 18 months in prison. Time the defendant had already spent in detention would be deducted from the one-year sentence, the judge said.

Setiawan told reporters after the trial that he would appeal the decision.

Munir's case has drawn widespread international attention and is seen as a test of how far the Indonesian government has reformed since the 1998 end of former dictator Suharto's New Order regime. Human rights groups have long accused Indonesia's intelligence agency of involvement in the killing, which it has denied.