Police are discouraging an Auckland group that has posted videos on Facebook of men the posters allege have responded to advertisements on Tinder for sex with underaged children.

The three respective videos - posted by people associated with a controversial European Students Association at Auckland University last year - show men talking to a member of the group who met them at locations arranged on Tinder.

In the first video, posted on Christmas Day, a young man is shown in a park at night.

"We had posed as an underaged child on Tinder, when this nonce, paedophile, predator, whatever you want to call him had solicited our decoy for sex," one of the group said on Facebook.


"He arranged to meet what he thought was an underaged child in a park at night. Little did he know we were waiting for him, to expose him for what he is: a child sex predator."

A second video, posted yesterday, shows a man alleged to have been "messaging what he thought was a 15-year-old boy for the past week".

"He invited our decoy to his apartment in Auckland's waterfront for the purposes of underaged sex, so we showed up with a camera," the post boasted.

The third video, posted in the early hours of this morning, shows a man in a car speeding off after he is approached by the group's decoy.

"He was here to meet what he thought was a 15-year-old girl for sex," the post says.

"Unfortunately he attempted to back out at the last minute and attempt to drive off, but not before I managed to approach him, and luckily we got his face on camera.

"Before you feel sorry for him, just remember that this creature had taken his dad's car out and drove halfway across Auckland to have sex with a minor, and unfortunately for him, we were there to catch him. Busted!!!

"This paedophile is only one of thousands that we have lined up to catch. Stay tuned for more videos in the coming days and weeks."

But a police spokesperson discouraged the group from taking the law into their own hands.

"Police encourage anyone who has concerns about potential offending to contact us immediately. All complaints will be taken seriously and followed up as appropriate," the spokesperson said.

"We strongly discourage members of the public from taking matters into their own hands as they could place themselves and members of the public at risk."

The spokesperson said police "are not able to respond to requests which seek to establish whether a specific individual is, or has been, under police investigation".

Two members of the vigilante group were also associated with a controversial European Students Association at Auckland University last year.

The association withdrew its application to affiliate to the Auckland University Students' Association after drawing fire for using Celtic symbols favoured by white supremacist groups.

A Herald investigation found that the association was part of an underground "alt-right" movement that sympathised with President Donald Trump and like-minded right-wing movements in the United States.

A member of the group told the Herald that he and a friend decided to expose paedophiles after reading a report by Greg Hallett alleging that top figures in the Government and the judiciary have been linked to child sex abuse. Hallett has also claimed that Hitler was a British agent and that the British monarchy is bent on world domination.

"He is a whistleblower," the group member said.

"We just thought there are so many sex offenders in New Zealand who are apparently getting name suppression.

"We've all heard stories about there being paedophiles in New Zealand who are not getting hard sentences. The police are not doing a particularly good job, so it's time for us to take matters into our own hands."

He said he and his friend had created a single fake account on Tinder and had received "hundreds" of replies from people trying to meet for what they believed would be sex with an underaged child.

"We have only had time to meet up with four," he said.

Three videos are still online, but he said a fourth, posted today, had been removed from Facebook, apparently because of its description of attempted underaged sex.

"They have banned me for 30 days and taken the post down," he said.

He said he was 22 and worked as a freelance share trader. His friend "works off a happy inheritance". Both of them therefore had time to keep pursuing the people who responded to their Tinder postings.

He said he hoped the postings would encourage the police to stage the same kind of stings.

"We hope the police, not necessarily with the cases that we have done, will take a stronger approach to catching paedophiles," he said.

Meanwhile in Australia, a man has been charged with grooming a 14-year-old child online after a vigilante set up his second filmed sting in a week.

The vigilante, who has dubbed himself the "Adelaide Pedo Hunter", executed the citizen's arrest of a 28-year-old man, who was later charged with procuring a child to commit an indecent act.

But the sting has prompted a second warning by SA Police against people taking the law into their own hands.

The set-up was filmed by the vigilante, who posted the video online on Sunday.