An Iranian asylum seeker detained on Nauru has attempted suicide, the first attempt since the centre was reopened almost exactly a month ago, on 14 September.

The man, whose identity and age remains unknown, was found hanging by the neck "turning blue" by fellow asylum seekers, according to Ian Rintoul from the Refugee Action Coalition (RAC), who received the news by phone from Nauru.

A spokesman for Immigration Minister Chris Bowen confirmed that a detainee had attempted "self harm" two days ago, but was not prepared to go into the "specifics of the self harm". Once staff became aware of the incident, "an officer intervened and he was immediately assessed and cleared of all physical harm," Bowen's spokesman said.

Rintoul believes the man is likely to be one of 20 Iranians who left Christmas Island for Nauru on 25 September.

The suicide attempt directly follows a visit by Bowen to Nauru earlier this week. Bowen addressed the detained asylum seekers, who told the RAC that he had said their claims would not begin to be processed for another eight months to a year — the time it would take to train assessors and interpreters.

Bowen's office confirmed the minister had spoken to detainees about the government's "no advantage" policy, and that all asylum seekers arriving in Australia or Nauru were being made aware of it, but that Bowen had made no specific statements on the duration of processing.

But after having spoken with asylum seekers currently on Nauru, Rintoul believes the suicide attempt was a direct result of Bowen's visit.

"Talking to the other guys, that's what they were anxious to tell us. The picture that I get is that the conditions in Nauru are quite bad and are being deliberately kept that way," Rintoul told NM.

"When Bowen actually came and made it clear that it would be eight to 12 months before you'll even be processed, and 'you'll be here for years' after that. That was the tipping point, not just for him, but for the rest of them."

Bowen's spokesman would not speculate on any "correlation" between the two events. "The individual's reasons for self-harm are his own," he said.

Suicide attempts, violence and hunger strikes at the detention centre at Nauru were a hallmark of the Howard government's Pacific solution.