In March, an 86-page government-commissioned review into abuse against Nauru asylum seekers revealed several dozen cases of sexual harassment and abuse at the detention center.
Long before the report was published the detention center staff "routinely" provided Australian authorities with detailed reports on assaults committed in the camp, covering both the cases described in March review and many other incidents, according to the open letter.
"The Government of Australia and the Department of Immigration and Border Protection have tolerated the physical and sexual assault of children, and the sexual harassment and assault of vulnerable women in the centre for more than 17 months," the open letter said.
Current and former staff of the camp called for the Australian public to support the transfer of vulnerable asylum seekers from Nauru to Australia. The letter urged people to seek an investigation into the assaults to be launched by the government.
The Nauru Regional Processing Center was established under a Memorandum of Understanding signed by the Australian and Nauruan governments in 2012.
As of February 2015, there were 742 asylum seekers held at the detention center, according to Australian Customs and Border Protection Service estimates.
Australia has been detaining people who attempt to enter the country without a valid visa since 1992.