An Australian man facing 25 hacking charges has fled to Europe, ahead of being trialled for his involvement in an international hacking ring targeting major computer firms, reports The Register.

The 19-year-old from Perth was arrested as a juvenile in May 2013 – hence they can't be named – and is said to have caused $100m in damages to victims Microsoft, Epic, Valve and the US Army. He is said to have stolen unreleased games including Call of Duty: Modern Warfare 3 and Gears of War 3 as well as an Apache helicopter training program.

Although the defendant admits to being a member of the hacking group, he denies breaking any Australian law. Included in the 25 charges he faces are six counts of unlawful use of a computer and seven counts of possessing child-exploitation material.

Australian authorities have issued an arrest warrant for the man and have alerted Interpol, while four other members of the group have already pleaded guilty in the US, and one was sentenced to 18 months in prison.

Speaking to The Australian from overseas, the defendant claims that "court delays" and "harassment by the West Australian Police" has made it impossible for him to fund his defense. He said he has spent $10,000 defending himself over the past two years, while the seizing of his computer in a police raid has made it impossible to do consultancy work, his primary source of income.

The defendant's lawyer, Andrew Chelvathurai, also questioned the police's tactics and says the charges against his client are unclear.

“The main reason for all these delays is that the authorities themselves are not clear on the charges,” he said. “Proving this case is going to be a real challenge for them … (my client) operated a few virtual servers on which he was system administrator, but that doesn’t mean he downloaded material himself.”

The Western Australian Police have refused to comment on these claims, but Deputy Director of Public Prosecutions, Bruno Fiannaca SC, said it was untrue that delays in the case had been caused by police or prosecutors.