An Australian army hero of the war in Afghanistan is being investigated by the Australian Army for allegedly murdering prisoners-of-war and other war crimes.

Australian prime minister Scott Morrison Thursday announced the formation of the Office of the Special Investigator (OSI) that will build criminal cases against men of the elite Special Operations Command suspected of committing war crimes in Afghanistan.

Morrison said OSI will be headed by a retired judge or senior criminal lawyer. He said this special investigative unit is needed because the workload involved in this contentious investigation will "seriously overwhelm" existing police resources.

"This report will be difficult news and all of our partners must be assured and those around the world who rightly hold the Australian Defense Forces in high regard," said Morrison.

"In Australia, we deal with this stuff and we deal with it honestly, but in accordance through the rule of law and by following the justice practices and principles that makes Australia what it is."

Prosecuting these alleged war criminals might take years, according to Morrison.

"These are incredibly complex events involving actions and conduct in another country, in a war," he pointed out.

OSI will look into allegations and rumors about the behavior of some soldiers in the Special Air Service and Commando Regiments in Afghanistan from 2005 and 2016.

Among those accused of war crimes is Benjamin Roberts-Smith, the most highly-decorated member of the Australian Defense Force and a member of the SAS. Roberts-Smith was awarded the Victoria Cross for Australia and the Medal for Gallantry for his heroism in Afghanistan. The Victoria Cross for Australia is the country's highest military award.

Roberts-Smith quit the SAS in 2013 with the rank of corporal. He was later accused by other SAS soldiers of unlawful treatment of prisoners, including illegally killing prisoners.

Roberts-Smith, who is now 42 years-old, has denied any misconduct. He's been the subject of a war crimes investigation by the Australian Federal Police since 2018. He's also been the subject of investigative stories conducted by different Australian media organizations.

Australian media firm Fairfax Media said its reporting of Roberts-Smith's alleged war crimes are "substantially true." It revealed a series of six unlawful killings alleged to have been carried out by Roberts-Smith in Afghanistan.

On Oct. 1, the Australian Federal Police told the federal court they have information, including a witness, that implicates Roberts-Smith in war crimes.

Defense Force Chief Gen. Angus Campbell will make public a redacted report on a four-year investigation of the war crimes allegations next week.