A Papua New Guinea national detention guard in Manus Island revealed more harrowing details of rape in the men's facility. The guard refused to be named in the fear of losing his job.

His revelation came after whistleblower, Rod St George, spoke of the same hapless condition in the Manus Island facility.

In an interview with Fairfax Media, the guard detailed of what he saw inside the facility involving a Pakistani victim who was raped by six Middle Eastern men.

"We had to go into the tent and he was there, and it was very bad. There was excrement all over the tent."

The guard said that the victim was given medical aid in the camp clinic for two weeks. BUT, the victim was sent back to the same facility where his rapists were roaming freely - something that was hard to understand.

According to the guard, there had been documents reporting the incident but there were no further investigations made and the PNG police remained clueless of what had happened.

Another rape case in May 2013 had compelled PNG nationals working for G4S to attend to the men's facility where another victim was raped and badly injured. But after that, the PNG nationals seemed still 'unaware' of what's happening.

One recent incident involved a brutal attack where a victim was slashed from shoulder to buttocks with a sharp object, "He had to go to the clinic. The cut went from his shoulder down to his buttocks."

But again, even with reports already filed, there were no investigations that took place.

The guard also revealed that G4S were guilty of exploitation for paying salaries of $40 a day.

In an answer to the issue, Immigration Minister Tony Burke said that officials were having a hard time investigating because witnesses and victims were not willing to name the culprits.

Mr Burke said, "There are challenges for the police in dealing with an allegation where no complainant has come forward and the only person who it is thought might have been a complainant that has left the country voluntarily some time ago.

In an interview with The Age, Mr Burke expressed confidence that current conditions in Manus Island will be improve by the Australian Labor Party's new policy.

He said that under the new policy, there will be separation of aggressive detainees from the vulnerable ones.

Mr Burke said, "I'm very confident that the accommodation on Manus will be able to keep well and truly in front of any attempts by people smugglers to test our resolve."