Story highlights Australia's highest court rejected extradition request from Hungary for suspected Nazi war criminal

Charles Zentai allegedly beat Jewish teen to death in 1944 for failing to wear Star of David

High Court ruled against request because "war crime" was not legal offence in Hungary in 1944

A naturalized Australian citizen, Zentai has maintained his innocence

Australia's High Court on Wednesday rejected an extradition request from Hungary for a suspected Nazi war criminal, ending a legal battle that began in 2005.

Charles Zentai and two fellow Hungarian soldiers allegedly beat a Jewish teenager to death in November 1944 for failing to wear the yellow Star of David. They are thought to have thrown the victim's body into the Danube River in the Hungarian capital, Budapest.

In a 5-1 decision, the court ruled that Zentai could not be extradited because "war crime" did not exist as a legal offence in Hungary in 1944, according to Australian media reports.

In doing so, it upheld a 2010 Australian federal court ruling against an extradition order approved by former home affairs minister Brendan O'Connor in 2009. Hungary issued an international arrest warrant and extradition request for Zentai in 2005.

Zentai, now 90, has maintained his innocence, arguing that he left Nazi-occupied Budapest before the crime occurred.

A resident of Perth in Western Australia, he has reportedly been living in the country since 1950 and is a naturalized Australian citizen.