Until today, she has been publicly defined by CCTV footage that shows her handcuffed, stripped of her underwear, stomped on, and kicked by police in a Ballarat cell. And she has been known only as "Person A" – the description given to her by an ongoing inquiry by Victoria's anti-corruption watchdog.

But now Yvonne Berry, who was a policewoman when she was allegedly assaulted by her colleagues in January 2015, has broken her silence in an exclusive interview with Fairfax Media and the ABC's 7.30 program.

Fairfax can also reveal that criminal charges laid against Ms Berry by local police after the Independent Broad-based Anti-corruption Commission launched its investigation last year have now been quietly withdrawn.

Ms Berry, a former detective senior constable, had been facing charges stemming from her night in custody, including resisting arrest and interfering with the good order of a jail – charges she describes as a "hamburger with the lot".

Police will now seek fresh advice from prosecutors about whether one of the officers who allegedly assaulted her should face criminal charges.

But the withdrawal in August of the charges against Ms Berry suggests they should never have been laid. This points to a broader phenomenon that many police privately concede occurs and which prominent defence lawyers and barristers such as Robert Stary and Dyson Hore-Lacy, SC, say is endemic: those who make allegations of police brutality are almost certain to face charges, even if they are not warranted.

If it can happen to a police officer aware of their rights in a cell with cameras, it can "happen to anyone" says Ms Berry, 52. "And I've since found out that it did and it does."

If it could happen to Ms Berry, what about the teenager at the back of the commission flats?

The two police officers alleged to have assaulted Ms Berry have been cleared to return to work.

But Ms Berry's ordeal has led to a rare mea culpa by senior police.

Professional Standards Command superintendent Tony De Ridder says he is "personally mortified" about her treatment in Ballarat's police cells, which he blames partly on "a total lack of leadership" in the police station.

"I thought on face value there were clear breaches of human rights and assaults had occurred, and I also thought the behaviour of our members was inconsistent with our training, the way we ask our people to behave. I was very shocked," he says.

Superintendent De Ridder says the force is "looking to change our culture totally so that human rights ... [are] embedded in everything we do".

A POLICEWOMAN'S TRAUMA

Ms Berry's journey to the Ballarat police cells on January 15, 2015, began many months earlier. In 2014, she took time off from the force after facing mental health issues she attributes partly to working as an internal affairs officer – who she says are still called "rats" by some police – and dealing with the horrific aftermath of the Black Saturday bushfires in 2009.

She is one of many officers who still carry the scars of dealing with families whose loved ones perished in the fires.

"I can still see the visions of all of that stuff today," she shudders.

Ms Berry is also not alone as an officer who turned to alcohol to self-medicate. On the evening of January 15, she was found drunk and incoherent by a Ballarat resident. The woman invited her into her home and called police, who arrested Ms Berry about 11pm after her clumsy, drunken efforts to run away.

Had she been treated in accordance with policy, she should have spent four hours in a cell to sober up and then been released, possibly with an infringement notice.

But she remained in police custody for 16 hours. In the early stages of her incarceration, the CCTV recorded her in a police cell attempting to use a broken drinking fountain before gesturing to the camera for water. Desperately thirsty, she then drank from the cell's toilet.

About 1am, Ms Berry became agitated, demanding a blanket and asking to speak to police, who didn't initially realise that she was a fellow officer. When the cell door was opened by a policewoman, Ms Berry pushed past, swiping the officer's lanyard. Ms Berry claims she noticed a capsicum spray bottle and reacted because she feared being sprayed. She struggled with two officers before copping a large dose of spray in her face.

Until this moment, Ms Berry could have been regarded as a vulnerable, albeit unruly, drunk woman in the care and custody of police. But she soon became a victim of conduct that senior law enforcement sources have described as "indefensible," "shambolic" and "a disgrace".

DRAGGED, STRIPPED, STOMPED ON

Ms Berry briefly wandered the station alone in a capsicum spray fog before she was handcuffed. She says the cuffs were ratcheted tight to cause pain; photos of her wrists taken later show deep bruising. She was then dragged on the floor by an officer to a cell. She was face down and still handcuffed when a male officer pulled down her underwear, apparently searching for the missing lanyard.

"I'm face down, I'm still handcuffed and I'd been sprayed. I was absolutely helpless," she recalls, still shaken by the memory of lying naked in front of male officers.

A policeman then stood on Ms Berry's feet and ankles. She was still naked. Next, he stomped on her ankle. He later told IBAC he was trying to stop Ms Berry kicking other officers. He was also filmed kicking Ms Berry. She says his explanation is ludicrous, as is the claim from a female officer filmed kicking Ms Berry that she did so to "calm her down".

"I was basically lying there like a fat jellyfish," says Ms Berry, who has photos of the injuries she says she sustained. They show an ankle crimson from deep bruising and which a doctor later said was fractured, and various bruises, cuts and welts on her body.

After her underwear was pulled back up by police, and wearing only a T-shirt, Ms Berry was taken to a shower, where she says she was scalded by hot water that also exacerbated the effects of the capsicum spray. She says she asked two policemen to turn down the water, a request they ignored. Instead, Ms Berry claims one of the officers said, in an apparent reference to her excess weight: "You're f---ing disgusting."

Later, as she lay in the cell, wet and covered with a blanket, Ms Berry had a moment of realisation. As a police officer, she had observed many "crooks" treated inhumanely. Now it was happening to her.

"I was absolutely horrified. Stressed, demoralised, and later on when I am in the cell, later on in the incident, I was just thinking I'm in Guantanamo Bay. This isn't Ballarat ... it can't be."

'THE HAMBURGER WITH THE LOT'

After Ms Berry was released from the police station, she says she was approached by IBAC to make a statement about what was captured on CCTV. She says the evidence should have prompted the charging of the officers who allegedly assaulted her.

But in February this year, she was notified in writing by police that there was "insufficient evidence to support a criminal prosecution in relation to allegations of assault".

Having been suspended, the two police accused of assaulting Ms Berry were reinstated. It is understood this has caused intense friction between IBAC and the force, with each blaming the other for various legal and administrative hurdles that impeded the investigation.

What is undeniable is that the only person to face charges has been Ms Berry, who last year left the police force on mental health grounds after 25 years' service.

Early this year, she was charged with criminal offences stemming from her night in custody, including resisting arrest and interfering with the good order of a jail. Ms Berry says she was being subjected to an old police tradition.

"In the police force, if someone has a set on you, they give you everything they can think of charge wise and it's called a hamburger with the lot. On the 8th of January this year, I got the hamburger."

She was also charged over the theft of a motor car, in connection to a stolen vehicle police found parked outside her home in country Victoria in December 2014, a month before her arrest.

A police member with knowledge of Ms Berry's charges says that despite police suspicions that a drunk Ms Berry drove the car, the case was not supported by firm evidence. The multiple charges arising from her 16 hours in custody were also deeply flawed, the source says.

"This is a classic case of police charging someone to cover their arses," says one of Ms Berry's supporters in the force.

The prospect of facing court left Ms Berry suicidal.

But in August, there was a reprieve. On the eve of her appearance at the Sunshine Magistrates Court and after advice from a senior barrister, all charges against her were quietly withdrawn by police.

MAKING CHANGES

Senior police expect IBAC's upcoming report into Ms Berry's treatment, along with treatment of other women allegedly manhandled at Ballarat police station, to be highly critical. The report is almost certain to focus on how the force previously dealt with persistent and high levels of complaints against some police at the station.

The officer leading efforts to improve the way the force deals with complaints is Assistant Commissioner Brett Guerin, an experienced and well-regarded policeman who says he is "after the same thing as IBAC".

Mr Guerin acknowledges police must improve the way they discipline their own and how they communicate with members of the public who complain about mistreatment, and do more to identify and retrain "high risk" officers subject to multiple complaints.

He insists "the culture is changing" and the changes are already producing dividends, including police willing to break ranks. An officer who slaps around a suspect is now at far greater risk of a colleague reporting them.

Calls for a new, totally independent police complaints body are misguided, Mr Guerin says, and change can and must be achieved from within.

"We need to own the issue of police misconduct, especially [towards] vulnerable people in custody," he says.

But leading criminal defence lawyers, such as Robert Stary and Dyson Hore-Lacy, SC, are sceptical about whether police are truly capable of investigating themselves.

Tamar Hopkins, a lawyer who has campaigned for years alongside the Flemington and Kensington Community Legal Centre for an independent police complaints body, says "there is more sunlight" creeping into the way police handle complaints. But while she says some senior police are committed to change, this is not enough to improve what is happening out on the street.

As for Ms Berry, she is taking matters into her own hands and plans to sue the force.

Her lawyer, Joseph Ridley of Arnold Thomas & Becker, said Ms Berry's case was not only about achieving justice for her, but about holding the police force to account on behalf of the community.

"I don't know that I will ever get past it. I dream about it," she says.

"I hope that the police force does do what they say they are going to do to look after people in custody – and weed out the ones who think they've got the power because they've got the badge."

TIMELINE

2014

• Yvonne Berry on stress leave from force's internal affairs section, suffering mental health issues.

2015

• January 15: Berry arrested for being drunk and taken to Ballarat police cells. Alleged assault captured on CCTV. Corruption watchdog IBAC alerted by police.
• April: Berry gives statement to IBAC, which announces public inquiry into Ballarat Police Station. Berry's identity is kept secret.
• April: Police Association mount legal challenge against IBAC's right to hold public hearings as part of its inquiry. This continues for months.

2016

• January: Berry is charged with multiple criminal offences, including those arising from her time in a cell and theft of a motor car in December 2014. She denies the charges.
• February: Police write to Berry, telling her none of the police who allegedly assaulted her will face charges.
• May: IBAC holds public hearing into Ballarat and releases CCTV of Berry's treatment. Her identity is kept secret.
• August: Police quietly withdraw charges against Berry after advice from senior barrister.
• October: With IBAC inquiry ongoing, Berry breaks her silence..
• October: Senior police respond, saying her treatment is unacceptable and committing to major reforms. Police also re-examining whether a police officer who allegedly assaulted Berry could be charged.