MISSING teenager Clancy Ellis was the victim of cyber-bullying on a social media website that’s been linked to numerous past teenage suicides.

The 15-year-old failed to return home on Wednesday morning and was last seen leaving a high school that day in Alstonville near Ballina on the NSW north coast.

It’s thought the teen could be on the Gold Coast, after she left a note for her parents which stated she was heading north and would be away for several months.

Retracing her daughter’s steps, Clancy’s mother has discovered the cyber-bullying the teen was subjected to on social networking site Ask.fm.

The site — which operates as an anonymous Q&A platform — encourages people to write what they honestly think of one another.

Clancy’s mother, Michelle Ellis, told Fairfax that the comments made about her daughter made her feel sick.

“Anonymous people were saying awful things about Clancy, just gross,” she said.

“And they threatened, ‘We know where you are, we know where your school is, we’re going to set up a Facebook page about you’.

“She suffered it all alone.”

Ms Ellis said Clancy had stopped reading books, which she loved, in the months leading up to her disappearance — and instead became constantly involved in social media.

“Some of my friends said, ‘Just shut down the internet,’ but I had professionals telling me you really can’t take away Clancy’s only form of communication,” she told Fairfax.

“We were scared that she would freak out. She would walk out of the house and keep walking, and basically do what she’s done.”

Her family have identified a few items the teen appears to have taken with her — including a mobile phone, laptop, clothes and a copy of The Hitchhiker’s Guide to the Galaxy.

A Facebook page, Help Find Clancy Ellis, has been set up by her family.

Police are continuing to investigate.

Ask.fm has been linked to several teen suicides worldwide.

The site was bought last year by the company behind the search engine Ask.com — with the new owners promising to stop bullying on the Q&A page or shut it down completely.

Doug Leeds, the CEO of Ask.com, said in an interview after the purchase: “We’re not going to run a bullying site … If we can’t [fix Ask.fm] we’ll shut it down.”

Police urge anyone with information about Clancy’s whereabouts to contact Crime Stoppers on 1800 333 000.

If you or someone you know needs help, please contact Lifeline on 13 11 14. There is also an anonymous online chat service available between 8pm and 4am AEST at Lifeline.org.au, or visit Beyond Blue’s website.

For crisis assistance, call 000.