Disturbing allegations of regular beatings, racist slurs and unwanted sexual advances by G4S guards on Manus Island have been made by a former Salvation Army worker.

Nicole Judge, a worker on the island, said she was "shocked and distressed" at the conditions on Manus Island when she arrived in September last year to work in a general support role.

Detention centre: Guards at Manus Island have been accused of violence, racism and sexual abuse against detainees.

In the three months Ms Judge was on the island, she claims in the submission to the Senate inquiry there was sexual activity in the so-called "rape dungeon" in one of the compounds and was told by the guards to carry a "rape whistle" while inside the centre. When she told Salvation Army staff that a young Myanmar asylum seeker was walking away from a toilet block in pain, her Salvation Army team leader dismissed her concerns, saying that "because these transferees are Muslim and actively engaging in prayer that any sexual activity would have been consensual". No follow up occurred, she says.

When another asylum seeker was being beaten against a wall and a metal bed frame to the point he was unconscious by two G4S guards, Ms Judge again complained to Salvation Army management, but was told she was "stupid" and "good luck".