Reports to ACMA of online child pornography increased by a third last year, but the watchdog says that doesn’t necessarily mean it’s more prevalent.

Reports of online child pornography jumped more than a third in 2013, new figures from the communications watchdog reveal.

The Australian Communications and Media Authority Hotline received 3075 such reports, up from 2283 in 2012.

The watchdog says 3258 investigations uncovered child sex abuse images and videos, up from 1282 in 2012.

There were an estimated 36,000 victims, the vast majority of whom were pre-pubescent girls aged about 13 and under.

The material was hosted in Australia in only four instances. Close to seven in 10 were hosted in the US.

ACMA hotline manager Jeremy Fenton said the figures did not necessarily indicate that child abuse is rising.

“It’s not a definitive view of the world,” he said. “Given the worldwide nature of the internet, it can’t be anything other than a window into that world.”

The increase in reports was probably due to greater awareness of the Hotline, which is partly the result of stronger ties with law enforcement agencies, he said.

When staff at the Hotline receive a complaint, they quickly assess its veracity and perform a technical trace to determine where it is hosted.

This is often difficult, Fenton says, because the criminals involved go to great lengths to mask their whereabouts.

If the material is hosted in Australia – usually on forums, image servers, and peer-to-peer sharing networks – the Hotline informs police then issues the host website a takedown notice.

Over the 14 years of the Hotline’s existence, every ACMA takedown notice has been successful, Fenton says.

If the material is hosted overseas, the ACMA refers the case to the relevant local branch of the International Association of Internet Hotlines (INHOPE), of which there are 49 globally.

It typically takes between one and three days from the time the ACMA or another INHOPE member receives a report from the public for the offending material to be wiped from the web.

In several cases, reports from the public have led to arrests and the removal of children from abusive situations.

In one instance, the Hotline received a report from the British Internet Watch Foundation that led Queensland police to an arrest within 24 hours, Fenton said.

“INHOPE is a remarkably effective network with a virtual global jurisdiction.”

* The public can report illegal online content to If you believe a child is in immediate danger, the ACMA says to contact the police on 000.