Telstra has redirected internet users that try to access child abuse materials more than 84,000 times since a voluntary filter program was enacted in July.
The carrier is one of four ISPs to sign on to filter a list of URLs containing child abuse material. The list is maintained by Interpol.
On visiting an infringing site, subscribers are redirected to a block page informing them of the website's material and providing a chance to appeal.
Neil Gaughan, head of the Australian Federal Police High Tech Crime Operations Centre, told a Senate Estimates hearing that the "open-ended trial" of the filter is growing with continuing expressions of interest from a number of ISPs.
However, Telstra remains the only ISP to offer statistics on the number of redirections to date.
Optus has operated the filter since the beginning of August, with at least another two small ISPs providing the option. An Optus spokesman did not respond to questions at the time of publication.
While providers are obligated to redirect or block users visiting offending sites under the filter initiative, they are yet to deliver the IP addresses of visitors to those sites to authorities.
Gaughan said it would be possible to obtain and act on the addresses.
The "worst of" list from Interpol is being used in place of a similar initiative by the Australian Communications and Media Authority, which continues to develop its own list of child abuse and refused classification websites.
It is believed there are several hundred URLs included on Interpol's list, with each website viewed and affirmed by at least two officers in separate, participating countries.
To be considered child abuse material, the site would have to depict real children younger than 13 years of age in an exploitative context.
The list is updated weekly and provided to ISPs through a secure virtual private network from AFP.
"It's pretty much difficult to do it any quicker than that," Gaughan said.
The trial is set to undergo a review in December, overseen by the Australia New Zealand Policing Advisory Agency's child protection committee.