The National Party is launching an immediate investigation after a troll social media account that had been harassing female Christchurch politicians was linked via an IP address of a member of the Young Nats.
National leader Christopher Luxon said he was appalled when he heard of "these completely repugnant and cowardly actions".
"No one should be subject to any form of bullying and I commend those affected for coming forward. National does not tolerate any bullying and the party will look into this under our new code of conduct."
National Party President Peter Goodfellow and Young Nats President Stephanie-Anne Ross also released a statement.
"The allegations reported today are appalling and we’re glad that those affected have shone a light on this behaviour. No one should be subject to harassment and bullying, either in person or online.
"We will be looking into this matter under our new code of conduct. This type of behaviour is not acceptable, and it is important for all parties concerned to see that it is stopped immediately."
Christchurch City Councillor Sara Templeton posted on Facebook today saying she was the "subject of a persistent online harassment campaign that went well beyond the normal trolling" during June and July last year.
"I had blocked the accounts, but they continued."
She said she attempted to find the person behind the accounts, after they disappeared once she "went public".
Templeton said other women were also targeted.
Stuff reported the profile, which went under the name Hamish Eggstein, also targeted Housing Minister Megan Woods and Labour's Sarah Pallett - both are electorate MPs in Christchurch.
The house which the IP address is linked to is owned by Bryce Beattie who is also a Young Nat and who denied any involvement.
Beattie released a statement on Facebook on his local board member candidate page saying that Wednesday was the first day he had been made aware of the online bullying aimed towards Templeton.
"I have had numerous different flatmates over the past twelve months, so as the homeowner I accept that this activity must have occurred from my property, however I reject entirely that I played any part in it or had any knowledge of it.
"I have also not been contacted by NetSafe or any other agency in regard to this matter and have only been made aware of it through a media approach. I am currently in the process of contacting NetSafe to try and uncover any information about this directly.
"While I have not always agreed with Councillor Sara Templeton's politics and ideology, I believe the best way to have a contest of ideas is by doing exactly what I am doing which is to put your hand up to represent your community at the October local body elections.
"I strongly believe that showing what I can offer as a local representative will always prove more constructive than directing abusive online comments towards those who you disagree with."
Young Nats is the youth wing of the National Party.