Reporter: Jeff Waters

Mark Colvin: There are growing fears for a group of ethnic Melanesian students in Indonesia who've been jailed for allegedly raising a banned flag during a peaceful protest.

Supporters of the group, from Indonesia's West Papua Province, say the prisoners have been charged with subversion, and are being mistreated in jail.

The cousin of one of the men is Herman Wainggai. He led a group of more than 40 Papuan asylum seekers to Australia two years ago. And as Jeff Waters reports, Herman Wainggai says he's worried his cousin will die in prison.

Jeff Waters: On the 3rd of March this year, a large group of Melanesian students gathered in central Manokwari in Indonesia's West Papua Province to call for a referendum on independence. It was one of a series of reportedly peaceful demonstrations held in the region in recent months.

Apparently a morning star flag, a nationalist Melanesian symbol, was raised. Police subsequently rounded up and arrested a number of demonstrators; one of them was Jack Wainggai, cousin of Herman Wainggai. Herman Wainggai was the subject of diplomatic tension between Jakarta and Canberra when he, his family and almost 40 others, were granted political asylum in Australia. Now Herman Wainggai says he's worried for his cousin's safety.

Herman Wainngai: I worry because my uncle die in prison. That's why now I'm really worried about my cousin. I don't want him to die when he's living in jail.

Jeff Waters: An Australian supporter of the Free Papua movement, activist Nick Chesterfield, says the prisoners are being mistreated.

Nick Chesterfield: Specifically in Manokwari, we've got very clear reports that each night Jack and his friends are being taken out and interrogated and very badly treated. They're being kept in damp cells, they're not being given enough food, they're not being given enough water and they're also having violent drunk criminals put in with them to attack them each night.

Jeff Waters: Campaign manager Andrew Beswick says Amnesty International is monitoring the case.

Andrew Beswick: Amnesty International doesn't support any political views necessarily on Papua one way or another. The political status there is a matter for the Indonesian people. What we say is that people have a right to express their political views and to do so peacefully, and they should not be in prison for doing so.

Jeff Waters: The spokesman for the Indonesian embassy in Canberra, Dino Kusnadi, says it would be inappropriate for him to comment on whether or not the men were arrested for raising a flag during a peaceful protest.

Dino Kusnadi: It's improper for me to elaborate on each individual cases as you ask me. But in general I can say that these people that's been detained, they have been charged, or they may have been charged with rebellion and subversive criminal acts.

Jeff Waters: But Mr Kusnadi disagreed that the prisoners would be mistreated.

Dino Kusnadi: We appreciate when we have reports like this we could report back to the proper authorities on whether that it is true or not. Of course, we have to acknowledge that there are limitations within the Indonesian police on the availability of jail cells.

Again, given with the attention of what's going on in Papua, the commitment of the central government, I'm sure that the authorities there will present their case as sound as possible before they go into the courts.

Mark Colvin: Dino Kusnadi, a spokesman for the Indonesian embassy in Canberra, ending that report by Jeff Waters.