CANBERRA, April 7 (Xinhua) -- One of Australia's most decorated soldiers was on Tuesday arrested by federal police over alleged war crimes committed in Afghanistan.

The Australian Federal Police (AFP) said in a statement that the former Australian Defense Force (ADF) member, aged 47, was arrested at Sydney Airport on Tuesday morning and is expected to be charged with five counts of the war crime of murder, which carries a maximum penalty of life imprisonment.

Local media identified the arrested man as Ben Roberts-Smith, a former special forces soldier who was in 2011 awarded the Victoria Cross, the highest award in the Australian honors system, for an "act of valor" during his fifth tour of Afghanistan in 2010.

The AFP said that the five alleged murders occurred in Afghanistan between 2009 and 2012.

It will be alleged in court that Roberts-Smith intentionally caused the death of a person in two incidents and aided, abetted, counseled or procured someone else to intentionally cause the death of a person in the other three incidents.

AFP Commissioner Krissy Barrett said at a press conference that it will be alleged that the victims were all unarmed Afghan nationals who were not taking part in hostilities at the time of their deaths.

"It will be alleged the victims were shot by the accused or shot by subordinate members of the ADF in the presence of and acting on the orders of the accused," she said.

She said that the arrest was the result of a complex joint investigation between the AFP and the Office of the Special Investigator (OSI).

The OSI was established by the federal government in 2021 after a landmark ADF inquiry found credible evidence that Australian soldiers had murdered at least 39 civilians in Afghanistan between 2005 and 2016.

Ross Barnett, director of investigations at the OSI, said on Tuesday that the arrest was a significant step.

"We'll continue this investigation until we get to the end point and wherever the evidence leads, that's where we'll go," he said.

"If the evidence leads to other people needing to be charged, you can be assured that will happen."

Speaking in Canberra, Prime Minister Anthony Albanese said he would not comment on any matter currently facing the legal system.

Roberts-Smith previously contested allegations that he was involved in war crimes in Afghanistan in a defamation lawsuit he brought against Nine Entertainment newspapers in 2019.

The Federal Court in 2023 ruled against Roberts-Smith, finding that it was substantially true that he had committed war crimes, and a subsequent appeal was dismissed.

Barnett said that the OSI has commenced 53 investigations since 2021 into alleged war crimes committed in Afghanistan, 39 of which have been finalized with no charges, with another 10 still ongoing.

The AFP in 2023 charged Oliver Schulz, a former member of the Special Air Service Regiment that Roberts-Smith also served in, with one count of the war crime of murder over the alleged shooting of an Afghan man in 2012, making him the first Australian in history to be charged with a war crime.

Schulz has pleaded not guilty and is set to face trial in 2027.