Some groups pose as children and set up meetings with those who are contacting them online

Gardaí say vigilante groups who aim to entrap online paedophiles could derail future trials of the people they target.

It comes as research on Safer Internet Day shows that one-third of the most vulnerable children regularly contact strangers online.

Juliette Gash reports:

Most of us are familiar with online paedophile hunters - vigilante groups who pose as children and set up meetings with those who are contacting them online.

While often well-intentioned, gardai are concerned about he legality of such actions, and say they have the potential for violence.

Assistant Garda Commissioner John O'Driscoll says they could also affect criminal proceedings.

He observed: "There is a danger that people who might otherwise be convicted of offences may not end up in such a scenario, and may go free because of the way in which the particular information has been handled."

Today is Safer Internet Day, when we're reminded how vulnerable children are online, particularly without supervision.

CyberSafe Ireland found that a third of kids who don't talk to their parents about online safety are in regular contact with a stranger.