THREE schoolgirls accused of being involved in the bullying that led to teenager Erin Gallagher's suicide were innocent and have themselves been bullied, the Irish Independent has learnt.
The homes of some of the girls have been vandalised, prompting gardai to give the families security advice.
One family has been forced to install a sophisticated home security system after intruders damaged cars at their property.
Erin was just 13 when she took her own life at her home in Ballybofey, Co Donegal, in October.
In the days following her death three teenagers were blamed for the cyber-bullying that Erin suffered on the controversial website Ask.fm.
One internet troll even set up a Facebook page naming one of the girls as a suspect and inviting people to leave hate comments.
However, gardai have now been told that all three schoolgirls had quit their Ask.fm accounts in June, four months before Erin's death.
The website allows users to post comments and direct statements anonymously to other users.
However, gardai now believe the bullies were posing as the three innocent girls to torment Erin.
They have obtained evidence that shows Erin was convinced the three girls were involved.
Officers have been forced to visit the homes of the three teens to offer security advice.
This follows vigilante attacks on the homes of two of them.
In one incident, paint bombs were thrown at a car at the side of one of their homes.
"Basically poor Erin thought these three girls were the ones taunting her but investigations have shown they couldn't have been involved," said one source.
"It now means that those who were actually targeting Erin have managed to escape blame-free at this stage."
Friends of two of the families told the Irish Independent their lives had been "turned upside down" since the teenager's death. "Parents were aware of issues with Ask.fm just before the summer and the fact that their girls were being targeted, and their accounts were closed down," said one family friend.
"They are devastated at Erin's tragic death but they are absolutely gutted that their girls are getting the blame. They've suffered horrendous verbal abuse and some vicious online abuse and are very much the victims in all of this."
Garda investigations into Erin's suicide are continuing.