The Australian government ignored allegations of physical and sexual abuse of asylum seekers held on the Pacific island of Nauru for more than a year without taking action, staff at the detention centre have alleged.

Twenty-three current and former staff signed an open letter calling for all remaining asylum seekers on the island to be sent to Australia and the detention centre to be shut down, the Guardian Australia reported yesterday.

Cambodia and Australia signed a pact to send refugees from Nauru to the Kingdom last September, but since the agreement was penned, a flood of allegations of abuse and self-harm have emerged.

A recent review of the centre’s conditions by former integrity commissioner Phillip Moss found some of the allegations were substantiated, sparking a Senate inquiry.

“We would like to inform the Australian public that the government and the Department of Immigration and Border Protection has been aware of the [allegations of] sexual and physical assault of women and children on Nauru for at least 17 months, long before the Moss review was ever commissioned,” the letter reads.