Even before he became one of Australia’s most high-profile whistleblowers, McBride led a colourful life.

After graduating from Oxford University with a law degree, he started his career with a stint in the British army. Leaving after reaching the rank of captain, he then tried his hand at everything from private security to reality TV and politics, before coming full circle and joining the Australian Defence Force (ADF).

As a legal officer, he did two tours of Afghanistan in 2011 and 2013, the latter with the special forces. It was then that he began to form the impression that “a line had been crossed” by commanders.

Over the next few years, and while suffering from undiagnosed post-traumatic stress disorder (PTSD) and abusing drugs and alcohol, McBride said he became more and more convinced he needed to speak up.

Working late into the night at an army base near Canberra, he started covertly copying hundreds of sensitive documents, smuggling them home in a backpack over 18 months.

He tried an internal complaint first. When that failed, he went to the police and the defence minister, before turning to the press.

He believed the dossier he compiled would show the ADF’s chain of command was so concerned about the perception of unlawful killings that they were scapegoating soldiers and undermining special forces’ confidence to do their work.

Instead, ABC journalist Dan Oakes found they contained evidence that Australian forces had committed war crimes and lied to conceal them.

“The more I looked into it, I couldn’t conceive how anyone would think these guys were being too tightly monitored. It was precisely the opposite,” he recently told the Four Corners programme.

“What happened out in the field stayed in the field.”

The Afghan Files, external included revelations military leaders themselves had concerns about a “warrior culture” within the force, and details of how soldiers were allegedly covering up the unlawful killings of unarmed men and children – including a six-year-old boy who was allegedly shot in his sleep in 2013.

Until that point, there had been very little reported about allegations of war crimes.

McBride was quickly fingered as the man behind the leak and he fled to Spain shortly before the Australian Federal Police (AFP) descended on his apartment. There officers found four plastic tubs filled with classified documents stashed in a cupboard.

After a year in hiding, McBride returned to Australia and was charged with stealing Commonwealth property, breaching the Defence Act and disclosing confidential information.

Police also started building a case against Mr Oakes and his producer Sam Clarke. In 2019, they dramatically raided the ABC’s Sydney headquarters and seized documents.

It was an unprecedented moment in Australia which made headlines around the globe. Under public pressure, prosecutors ultimately decided against charging the journalists, arguing doing so would not be in the public interest.

Within a month, the findings of a landmark inquiry known as the Brereton report found credible evidence of unlawful killings of civilians and prisoners in Afghanistan from 2007 to 2013.

The government also set up the Office of Special Investigator to begin criminal investigations into the allegations. Only one person has been charged so far.

But despite mounting pressure, the government refused to order prosecutors to drop the case against McBride.