Jakarta – Five years after the murder of prominent human rights activist Munir Said Thalib, his supporters have accused the government of lacking resolve to settle the case.

State prosecutors have said they simply lack the certified copy of the ruling needed to pursue a case review.

"Without it we cannot formulate any argument to use for the case review," Jasman Pandjaitan, a spokesman for the Indonesian attorney-general's office said on Monday.

He said activists could help by trying to get a certified copy of the Supreme Court ruling. "We have the same concerns [as activists]. Therefore, don't heap the blame on us," Jasman said.

Munir was an outspoken critic of Indonesia's military and its methods of quashing dissent and separatism in provinces such as Aceh and Papua.

He was poisoned by an off-duty pilot on Indonesia's national carrier, Garuda Airlines, while flying from Jakarta to Amsterdam in September 2004.

The pilot, Pollycarpus Priyanto, was jailed for 20 years in January, after being initially acquitted while Indra Setiawan, former Garuda chief executive, was also found guilty of being an accessory to Munir's murder and sentenced to one year in jail.

Official autopsy results revealed Munir's death was due to arsenic poisoning.

His widow Suciwati, a former labour activist, said the AGO's excuse was a mere "technicality". "Why on earth are the prosecutors waiting for the copy of the ruling to arrive on their desks? This kind of technicality simply represents the AGO's lack of seriousness in their approach to this case," she said.

Suciwati joined a rally in front of the attorney-general's office Monday, later meeting with Jasman.

State prosecutors had said they would file a review against a Supreme Court ruling last December that saw former state intelligence deputy chief Muchdi Purwopranjono acquitted of all charges of masterminding the murder.

In June, the Supreme Court dismissed an appeal filed by state prosecutors against the court's decision to acquit Muchdi.

There have been some suggestions during the investigation however that the Indonesian secret services were involved in the murder. The United States, the European Union and the United Nations have all asked Indonesia to do more to investigate Munir's death.