Fourteen men, including fathers, have been arrested across eastern Australia following the discovery of hundreds of thousands of pornographic images and videos of children.
Australian Federal Police (AFP) searched 19 premises in Victoria, NSW, Queensland and the ACT and laid 27 charges after receiving a tip-off from Interpol last December.
The peer-to-peer file sharing network, which involves the sharing of information without using a central server, was originally discovered in Germany.
AFP cybercrime operations manager Glen McEwen said hundreds of thousands of images and videos were seized and some involved toddlers.
"They are atrocious," he told reporters in Melbourne on Friday. "Allow me to place on record my personal disgust of the abhorrent nature of activity associated with the exploitation of children."
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The arrested men were aged between 21 to 64 and some were fathers, Commander McEwen said.
"The reach of the internet, which has no geographical physical boundaries, attracts all walks of life," Commander McEwen said. "You just never know who could be involved in this."
The charges cover accessing, making available and possessing child pornography. The terabytes of images and videos were found on hard drives, laptops, mobile phones and portable storage devices.
Commander McEwen said the AFP would work with international agencies to determine the identities of the victims depicted.
He said he didn't know if any Australian children were involved but various ethnicities were represented in the material. A 15th man was assisting the AFP with its inquiries.
The Victorian men were arrested in Warranwood, Bulleen, Kings Park, Croydon and Southbank.
In NSW, arrests were made in Colyton, Neutral Bay, Petersham, Carramar and Dulwich Hill, while in Queensland police made arrests in Mount Warren Park. Police also arrested men in Franklin and MacGregor in the ACT.
A 21-year-old Bulleen man and Warranwood man, aged 62, were expected to face the Melbourne Magistrates Court on Friday.
Federal Justice Minister Jason Clare welcomed the arrests which followed a covert AFP operation code named Operation Belfort.
"This is a really important breakthrough - smashing an alleged child exploitation ring and taking hundreds of thousands of child exploitation images and videos out of circulation," he said in a statement.
