Police have shut down one of the largest child sex exploitation rings seen in Australia that was dealing in "abhorrent and disgusting" images, officials have said.

Twenty-one people aged between 22 and 76 from around the country were arrested and charged, the Australian Federal Police (AFP) announced on Friday.

Police said they had also identified one child aged under 10 who was known to one of those charged and who appeared in some of the material.

"The material seized can only be described as abhorrent and personally disgusting," said Glen McEwen, cyber crime operations commander.

Thousands of images

The operation began in January when a number of people were identified by the AFP using a file-sharing network that contained images of children of different ages being sexually abused.

Police are now sifting through thousands of images, with 26 hard drives found in one home alone, after executing search warrants on close to 40 premises during the week.

The network allowed those involved to access and download material from each other's computers.

"When you look at previous operations of similar activity, this is one of the largest," McEwen said.

One of those arrested was a woman, which police considered unusual for this type of crime, local media reported.

If convicted, the suspects could face up to 15 years in prison with offences including accessing, producing, transmitting and making available child exploitation material.

McEwen said the investigation showed that offenders could not escape the law.

"This operation shows that the internet is not anonymous and if you are involved, or choose to groom children online, or be involved in the production, distribution or access of online child abuse, you will be pursued," he said.

Source: Agencies