The suspect, Gerard Peter Scully, 51, was arrested in the southern Philippines city of Malaybalay last month after allegedly sexually abusing at least eight girls, including an 18-month-old infant.
He also allegedly strangled one of the girls to death, with her skeleton later discovered buried under a house he had rented, investigators said.
A complaint, filed by Justice Department investigators with the prosecutors' office, said Scully forced the girls to perform sexual acts in front of a video camera for paying clients overseas.
"Wherever these syndicates are, we will hunt them down and we will bring them to justice."
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In the complaint outlining the case against Scully, a 13-year-old girl was quoted as saying that her impoverished family agreed she could do domestic work at his home in 2012.
But she was instead forced to perform sex acts with other girls, and was beaten by Scully's Filipina girlfriend when she refused, according to the prosectors' complaint.
The girl said she fled Scully's house after she learned he had sold her to a German national who was coming to collect her, the complaint said.
The head of the anti-human trafficking division of the justice department's investigating arm, Eric Nuqui, said that Scully had been the subject of an international probe after Netherlands police found out about his activities.
If convicted, the Australian could face life in prison.
Last year, de Lima said that online child abuse was the leading cyber-related crime in the Philippines, making up 46 percent of the more than 200 cases being handled by law-enforcement agencies.