The activist, Munir Said Thalib, died aged 38 as he travelled from Jakarta to Amsterdam in September 2004, poisoned with arsenic by an off-duty Garuda pilot accused of links to Indonesia's powerful intelligence agency, BIN.

The secretary, Rohainil Aini, was accused of working to issue a falsified document which allowed the pilot, Pollycarpus Priyanto, to board a flight taken by Munir from Jakarta to Singapore en route to the Netherlands.

'Rohainil Aini was not proven to be involved in the premeditated murder of Munir. For that reason the defendant must be cleared of all accusations,' the head of the panel of judges, Makassau, told the Central Jakarta district court.

'The issuing of a document for Pollycarpus was in conformity with her job description,' Mr Makassau said, adding that the defendant had no authority to check the document she was asked to prepare.

An Indonesian court on Monday sentenced the former boss of Garuda, Indra Setiawan, to one year in jail for assisting in Munir's murder.

Setiawan told the court during his trial that BIN officers had asked him to assign Priyanto to Munir's flight in a letter marked 'secret' sent in April or May 2004.

He said the letter disappeared from his car in December 2004.

The Supreme Court ruled last month that Priyanto was guilty of killing Munir and sentenced him to 20 years in prison.

Munir had provided legal counsel for victims of officially-sanctioned violence during former president Suharto's 32-year rule.

His case has elicited widespread international attention and is seen as a test of how far the Indonesian government has reformed since Suharto stepped down amid riots in 1998. -- AFP