Family and supporters accused the military of involvement, but senior officials have always denied the allegations.

Mr Eluay and four members of the Papua Presidium had been on trial, charged with treason for trying to set up an independent state of West Papua.

"The temporary conclusion is three rogue officers of the Indonesian military must go through a legal probe as suspects. They have been detained," the military said in a statement.

Eluay was found dead in his overturned car

Major General Sulaiman Ahmad Basir said the three men were part of a special forces group based in Papua, where they participated in the military crackdown against separatists who have been fighting for independence for nearly 40 years.

The government has ruled out full independence for the province, which lies on the western half of New Guinea island, but it hopes more autonomy will end the fighting.

A former Dutch colony, West Papua - formerly known as Irian Jaya - was formally annexed by Indonesia in 1969 after a UN sanctioned referendum that critics have dismissed as a whitewash.