Your child's school photo might be cute as a button, but think twice before sharing it online. In the wrong hands it can be manipulated into the kind of image any decent person would wish didn't exist.

Senior staff at the Australian Federal Police have added their voice to warnings that ordinary images can be sexualised, and the best way to avoid this was to not share images too widely online. The advice follows revelations last week from the Children's eSafety Commissioner's that millions of innocent photos posted to social media had been found on websites sharing child exploitation material.

"Once you post an image, you lose control," the AFP's Manager of Victim Based Crime, Commander Glen McEwen, told Fairfax Media.

While it was unrealistic to expect parents, teenagers and children to stop sharing photos completely, he suggested they think carefully before putting an image on the internet.

"Certainly the potential [for the photo to be copied] is there, it is real, and it is present," he said.

The danger to children was that images could be misrepresented or doctored. The AFP has found instances where school photos originally posted on social media had been photo-shopped so that a child's face and the perpetrator's were both pasted into an abusive image.

It was also possible that geo-location and visual information could provide clues about a child's location. And "depending on the predisposition of the predator, this could be dangerous", Commander McEwan warned.

"Unfortunately the world of paedophilia is very unstructured and very unpredictable," he added.

He was unable to confirm any instances where Australian children had been abused or abducted because of photos posted to social media. Fortunately the reverse has occurred, where the AFP has been able to track down and rescue children from abusive situations because of photos posted online.

Australian law enforcement, via the AFP, co-operates closely with the US National Centre for Missing and Exploited Children, which last year passed on thousands of tips to the AFP about exploitation material that was in some way linked to Australians.

Meanwhile, on Thursday the eSafety Commissioner announced it had new partnerships with nine social media companies to take down offensive material within 12 hours on request. Four companies - Google Plus, Facebook, Instagram and YouTube - are now legally bound to take bullying material down within two days if requested to do so. And the office has completed 2057 investigations into illegal material posted online since it was set up three months ago.