When prison guard Chris Bryant (not his real name) left work at Canberra's Alexander Maconochie Correctional Centre on Christmas Eve in 2013, police were waiting to arrest him.

Days earlier, in a series of long interviews, his former fiancée had described in graphic detail how Mr Bryant had brutalised her during their two-year relationship.

She told police he raped her twice, struck her with a tyre lever, bashed her with his fist and elbow, broke her nose and even urinated on her.

She took out an Apprehended Violence Order, but she said the abuse never stopped.

Not only was Mr Bryant arrested, but he would spend more than four months in Goulburn jail, one of the country's toughest prisons.

There was just one problem: the allegations were false.

The charges against Mr Bryant were eventually dropped and the supposed victim has been exposed as an accomplished liar.

Got a confidential news tip? Email ABC Investigations at investigations@abc.net.au For more sensitive information: Text message using the Signal phone app +61 436 369 072 No system is 100 per cent secure, but the Signal app uses end-to-end encryption and can protect your identity. Please read the terms and conditions.

Details of this extraordinary miscarriage of justice have emerged in court documents and hearings in the ACT in recent months.

The case raises serious questions about the conduct of the Australian Federal Police (AFP) officers involved in the investigation which led to Mr Bryant's incarceration.

A New South Wales police officer — the woman's current boyfriend — is also under investigation.

On August 26, Mr Bryant's accuser — a former New South Wales Police employee who cannot be named for legal reasons — was found guilty of two counts of making a false accusation to police and two counts of public mischief.

In an interview with the ABC, Mr Bryant said the four-and-a-half months he spent in Goulburn jail were "gut-wrenching".

"You're in a place that you know you don't belong, you haven't done anything to get here," he said.

The trouble started when Mr Bryant broke off their engagement in November 2013.

"She was devastated. She was planning this wedding from almost two months into our relationship," he said.

"Her 'happy ever after' [was] not coming to fruition."

After finding the woman guilty last month, ACT Chief Magistrate Lorraine Walker said her conduct "could properly be characterised as a vendetta".

The chief magistrate described some of her allegations as "highly implausible" and suggested some of the woman's injuries may have been self-inflicted.

One crucial piece of evidence, a condom wrapper found at the scene of one of the alleged rapes, was later forensically tested. Hers was the only DNA found on it.

The court also heard that, years earlier, she had accused another man of sexually assaulting her. This allegation was investigated at the time and found to be baseless.

Motive 'one of the oldest in the book'

Mr Bryant and his girlfriend had one major asset: a Canberra property they had purchased together. After they broke up, Mr Bryant's former partner demanded a greater share of the proceeds.

Prosecutor Anthony Williamson told the ACT Magistrates Court her motive was, "one of the oldest in the book and it's greed, pure and simple".

This photo of the former prison guard with his nephew was taken around the time of one of the alleged rapes. ( Supplied )

In her judgement, the Chief Magistrate alluded to the woman's ability to manipulate police with her extreme tale of domestic violence.

"Sensing a receptive audience, she let loose," Ms Walker said.

After he was arrested, Mr Bryant's bail conditions meant he could not leave his parent's house without one of them.

"Police would often come over, trying to get me on a breach of bail," he said.

In March last year he was arrested again. He was accused of arriving at the house they once shared, slamming his former fiancée's head against a wall, before raping and threatening to kill her.

Later that day, officers jumped the fence at his parents' house. They threatened to "gas" him with capsicum spray if he resisted when they handcuffed him.

Mr Bryant was remanded in custody but sending him to the Alexander Maconochie Centre, where he had worked for almost a year, was out of the question. Instead he was sent to Goulburn jail.

"As a prison guard you're the worst of the worst on the prison hierarchy," Mr Bryant's lawyer Peter Woodhouse said.

"You're worse than a paedophile, you're worse than a police officer."

For his own protection Mr Bryant was placed in an isolation unit where he became suicidal.

"You'd be looking at a radio going, yeah that cord and, yeah, that shower, or the bunk bed, that could do it," he said.

Former acting sergeant pressured fellow officer, ABC understands

At least two police officers involved in the case have been investigated in separate probes by NSW Police and the AFP.

The ABC understands a former AFP acting sergeant pressured a fellow officer to change her statement in relation to one of the alleged rapes.

A professional standards investigation found the acting sergeant, who later resigned, threatened another AFP officer.

Internal AFP documents, obtained under Freedom of Information, showed the same officer was warned he had become "too personally involved" with the alleged victim and this could leave him "open to allegations of interference" later on.

The accuser's boyfriend, a NSW police officer, gave evidence at the woman's trial corroborating parts of her story. He is now being investigated by NSW Police.

Mr Woodhouse believed the woman clearly understood how the criminal justice system worked in the ACT, particularly the bail laws.

"You wouldn't expect her to have that knowledge," he said.

"You might expect her boyfriend, the NSW police officer, to have the knowledge and you would definitely expect an AFP police officer to have that knowledge.

"That to me suggests that the conspiracy was not hers alone."

Mr Bryant's former neighbour said she had discussed the property dispute with the police officer boyfriend.

She told the ACT Magistrates Court: "It was [their] intention to try and draw as many incidents together of criminal activity" implicating Chris Bryant and "if there was a good body of criminal activity ... they were likely to be awarded 100 per cent of the property".

Lawyer says case always 'doomed to fail'

Mr Woodhouse has told the ABC the prosecutors who pursued Mr Bryant must also shoulder some of the blame.

"It should have been obvious, at least from July 2014, that this matter was doomed to fail," he said.

"They continued the prosecution for at least another two months and it was only when we issued a subpoena to the AFP seeking information about one of the officers that the matter was dropped."

The Director of Public Prosecutions (DPP) in the ACT, Jon White, Senior Counsel, said his office relied heavily on the evidence provided by police in its case against Mr Bryant.

"Upon review of the previous complaints, detectives became suspicious [the woman] had provided fabricated evidence to police," he said.

"Through careful investigation, a brief of evidence against [her] was assembled."

When the original investigation was re-examined, another important piece of evidence emerged: a digital photograph of Mr Bryant taken around the time of one of the alleged rapes.

His legal team had advised him not to tell police about this partial alibi.

"It is very dangerous to show your cards as an accused person," Mr Woodhouse said.

"That's the reason that the alibi wasn't raised earlier on."

The DPP said had its office known, Mr Bryant may have been released from custody sooner.

"It goes without saying that the incarceration of an innocent person is a matter of significant concern and regret," Mr White said.

"It should never happen."

The AFP declined to answer any of the ABC's questions as part of this story.

"She was in a relationship with another copper and cops look after cops, it's as simple as that," Mr Bryant said.

He believed his former fiancée — who is currently receiving a psychiatric assessment and is due to be sentenced next month — was motivated by greed and vengeance.

When she was convicted last month she mouthed the words "I love you" to her current partner.

"You've got people who've actually gone through rape and you know she's made a mockery of that," Mr Bryant said.