Water was available at all times from inside the cell.
A spokesman for GEO Group Australia, the private operator of Ravenhall, confirmed a staff member had been suspended from duty while it investigated the claims, but refused to provide details.
A review of forensic mental health services at Ravenhall, obtained by The Age in November, described chronic staff shortages, compromised patient care and chaotic leadership since it opened in October 2017 as a 1000-bed prison.
The Andrews government later activated a clause in its contract with GEO Group to increase the population to 1300.
An Andrews government spokeswoman said: “We expect all correctional staff to act to the highest standards at all times and that any allegations of misconduct are thoroughly investigated.
“As this matter is now under investigation, it would be inappropriate to comment further.”
Treatment of Aboriginal people in custody is facing renewed scrutiny after two recent Victorian deaths.
Yorta Yorta woman Veronica Marie Nelson Walker was found dead in the government-run Dame Phyllis Frost Centre, next door to Ravenhall, on January 2.
Ms Walker’s family has since questioned the supervision provided by Corrections staff while she was held in an observation cell after being refused bail for alleged shoplifting.
In March, coroner Caitlin English is expected to hand down her findings into the death in custody of another Yorta Yorta woman, Tanya Day.
Ms Day, a 55-year-old grandmother, fell and suffered a head injury while in a regional Victorian police cell after being arrested for drunkenness on a train on December 5, 2017. She died two weeks later.
Opposition corrections spokesman David Southwick criticised the government’s handling of the “chaotic” prison system and called on Premier Daniel Andrews to provide transparency over “another internal investigation and buried reports”.
“The community deserves answers into these incidents and to know just what is going on behind our prison walls,” he said.
Zach is a reporter at The Age. Got a story? Email me at firstname.lastname@example.org