A woman arrested for drunkenness in Ballarat was allegedly pepper-sprayed, partially stripped, kicked and left in a police cell for hours without her pants and had to drink water from a toilet.
A complaint about her brutal treatment is being examined by Victoria's anti-corruption watchdog.
Investigators have uncovered many complaints, over a number of years, of police assault or failure to perform duty of behaviour at the Ballarat Uniform Police Service Area.
Counsel assisting Jack Rush QC on Monday told the inquiry Ballarat has more than three times the average number of assault complaints made against its officers compared to similar stations.
Initially, inexperienced officers were blamed for the high number of complaints, but collation of the complaints in 2012 found senior and experienced officers accounted for the majority of allegations.
The discovery prompted a plan to tackle the abusive behaviour, but in the years since "complaint levels have remained constant and high", Mr Rush said.
The inquiry will hear of four case studies, including that of a woman, 51, who was arrested in January last year for public drunkenness and taken to the police cells.
"She was kicked, stomped and stood upon," Mr Rush said as he opened the week-long hearings in Ballarat.
He said the woman, who cannot be named and is known as person A, was held in the cells for about 16 hours, despite being told it would only be for four.
Mr Rush says security tapes played to the hearing show the woman lying on her stomach with her hands cuffed behind her back. It also showed her using a paper cup to drink out of a toilet because the fountain in the cell was broken.
This was after being pepper-sprayed during a scuffle over a lanyard she had taken from a police officer.
She was searched by having her pants pulled down from her so that she was left only wearing a T-shirt, bra and panties, he said.
"Those panties were at one stage positioned between her bottom and her knees and all this occurring in the presence of male officers, whilst lying prostrate on the ground covered with (pepper) spray around her facial area," he said.
After being pepper-sprayed, she was then left handcuffed in a shower for 20 minutes - which magnified the burning effect, Mr Rush said.
One 95-kilogram officer who stood on the woman's legs while she was in the cell claimed it was because: "I thought there was a threat I was going to be kicked, it was a knee-jerk reaction".
"She was quite aggressive in her tone and her language. I was in a prime position to get kicked," he told the hearing.
He also denied he had deliberately kicked the woman.
"I wasn't going to take any chances," he said.
"People don't get foamed for no reason."
The three other case studies also involve the treatment of women, including two mothers who went to the station, one in 2009 the other in 2010, to inquire about their sons' arrests.
