Fresh warnings on Snapchat dangers after schoolgirls targeted

Australia's e-safety commissioner has warned young people about the dangers of photo-sharing apps such as Snapchat after Sydney schoolgirls were targeted in a dangerous scam.

Commissioner Julie Inman Grant said new features on Snapchat such as "Memories" and "My Eyes Only" allowed users to store images they were sent.

"We received a complaint from a parent about the use of Snapchat among a group of friends at a school," she said.

Ms Inman Grant said it appeared the group of female friends had been manipulated into sharing their Snapchat passwords and PIN numbers, which led to some private images being distributed without consent.

"Unfortunately it's a very sad, cautionary tale and one we're seeing far too much in this brave new online world," she told 9NEWS.

She said the most expedient way to have private images removed from the network was for parents to contact the social media body.

However, she also encouraged people to contact the national e-safety body.

Preventative measures also existed.

"Sharing isn't always caring when it comes to passwords," Ms Inman Grant said.

"Be very careful about the images you do share."

She said it was important for parents to maintain an open conversation with children on the issue.

Young people tended to migrate once they believed they were being too closely monitored - with many teens now shifting to a Korean image-sharing app called Snow.

Other schools across Sydney have been alerted to the scam.