At least 10 lawyers have offered to provide legal aid to six suspects recently accused of treason in relation to a deadly police crackdown in Papua, a human rights watchdog says.

“There will be around 10 lawyers to assist [the suspects],” Olga Hamadi from the Commission for Missing Persons and Victims of Violence (Kontras) said Friday as quoted by tempointeraktif.com.

Olga added that the six suspects had been interrogated by police on Thursday without any legal representatives.

“Yesterday we met with the investigators and suspects. A few friends and I took Selpius Bobi to Papua Police. He was the Congress organizing committee chief and the suspects had no lawyers,” he said.

Olga said several organizations including the Democratic Alliance for Papua and Kontras Papua had stated their willingness to provide the suspects with legal aid.

The six congress participants who have been named suspects include: Papua indigenous council chief Forkorus Yebosembut, Edison Gladius from the West Papua National Authority and Papua human rights activists August Makbrawen Sananay Kraar and Dominikus Sirabut.

The suspects have been charged with treason and possession of weapons.

Around 4000 people took part in the third Papuan Congress on Wednesday. Police reportedly opened fire at members of the congress after the outlawed "Morning Star" flag was raised.

Five people were reported dead after the incident, their bodies found not far from a nearby military compound. Meanwhile, dozens of participants in the congress were reportedly punched and beaten with rifle butts and batons.

The local police have denied using excessive force.

Meanwhile, the international community has become increasingly critical of Indonesian authorities in Papua, following a long history of violence in its eastern-most province.