Three Australians were part of a webcam ring which allowed paedophiles to pay to watch children as young as six being sexually abused in the Philippines.

The crime ring has been dismantled after a joint investigation by the UK's National Crime Agency (NCA), the Australian Federal Police (AFP) and US Immigration and Customs Enforcement (ICE).

A total of 29 people were arrested, including two West Australian men and one Sydney man who was arrested by the Royal Thai Police in Bangkok.

The investigation turned up hundreds of thousands of images and videos depicting online child sexual exploitation, including children as young as six.

The Australians allegedly financed and ordered the child exploitation shows, which were organised by an organised crime group in the Philippines.

One of the Australians, a 53-year-old from West Perth, was sentenced in October 2013 to 24 months in jail with a minimum term of 12 months.

A 52-year-old man from Como in Western Australia has pleaded guilty to offences including accessing, transmitting and making available child exploitation material.

He will be sentenced on January 24.

The abuse involved 15 children in the Philippines aged between six and 15.

Of the 29 people arrested, 11 were part of the facilitation group in the Philippines.

Some of the facilitators were members of the children's own families.

Children 'rescued from living nightmare'

AFP Assistant Commissioner Tim Morris has described the crimes as "abhorrent".

"The use of online media to drive these types of crimes is a sinister development," he said in a statement.

"To target the most vulnerable members of the community in this way cannot be tolerated in any society.

"It's abhorrent that these crimes occur and it is our duty as police and the wider community to ensure that every possible measure is taken to identify and assist the victims and to identify and take action against the perpetrators."

ICE Homeland Security Investigations (HSI) executive associate director James Dinkins says the children were "rescued from a living nightmare".

"The group responsible for these heinous crimes mistakenly believed that they could use technology to avoid detection, but they were wrong," he said.

"We will continue to work tirelessly with our international law enforcement partners across jurisdictions and national boundaries to protect children anywhere in the world and bring criminals to justice regardless of where they live."

All of the victims rescued were placed in the custody of the Philippine Department of Social Welfare and Development.

Routine visit to sex offender's house sparked investigation

The investigation began after British police carried out a routine visit at the home of registered sex offender Timothy Ford.

Police found a number of child exploitation videos on computers in his home, sparking a global investigation which led police to the Philippines.

The AFP and other organisations were contacted for help in August 2012.

Police say that in addition to paying for the live abuse of children, Ford planned on moving to the Philippines to set up an internet cafe.

Investigations into his activities and the wider customer network he was associated with identified other suspects including a man named Thomas Owen.

Owen was found to be in possession of nearly 4 million indecent images of children.

Evidence shows Ford and Owen discussed online how they could travel to the Philippines to abuse children.

In one chat log Ford, who uses a wheelchair, suggests that Owen could act as his carer so they could travel to the Philippines together in an attempt to avoid detection.

Within the UK there have been 17 arrests which have so far resulted in five convictions, including Ford and Owen.

Ford was sentenced in March to eight-and-a-half years in prison, while Owen was sentenced to seven years in jail last July.

Hans Guijit from the children's charity, Terre des Hommes, told the BBC that the abusers were exploiting desperate people.

"These people are poor and this is all about survival. For them, they think it the only way out of the poverty trap," he said.

"There is a huge demand for this kind of sexual activities - at any given moment in time there are 750,000 men looking to engage children into this kind of sexual activities."