Deon Swiggs, former central city ward Christchurch city councillor, says he is exasperated a code of conduct complaint will not be investigated.

A code of conduct complaint against former Christchurch City councillor Deon Swiggs will not be investigated as he is no longer a councillor.

Council chief executive Dawn Baxendale advised Swiggs' lawyer Phil Shamy of the decision by letter on Thursday afternoon.

Swiggs was ousted from his central city seat at October's local body election, three weeks after allegations were made public that he sent "grossly inappropriate" messages to youngsters. Swiggs denies the allegations.

CHRIS SKELTON/STUFF Christchurch City Councillor Deon Swiggs, who denied sending "grossly inappropriate" messages to three young people, has lost his Christchurch Central ward. (First published on October 3.)

Baxendale said Swiggs was no longer a councillor, the code of conduct should be enforced against sitting councillors, and there was "no meaningful provision of the code that would enable the council to take action against Mr Swiggs, should the complaints against him be proven".

Swiggs said he was exasperated by the decision.

"The fact they are letting the materiality finding stand, leaves a black mark against my name. I will now look at ways to clear this, including filing for a High Court judicial review of the council's process."

Retired High Court judge John Matthews found two complaints against Swiggs were material and required a full code of conduct investigation.

Three complaints were dismissed as they related to his conduct outside his term of office.

Of those three, one – which allegedly took place in 2013 when the complainant was 15 – was referred to "another agency", which appears to be the police.

Matthews put the council's investigation on hold until after the local body elections on October 12.

Swiggs lost his seat to People's Choice/Labour candidate Jake McLellan.

In the letter to Swiggs' lawyer Baxendale said there was no provision in the Code for quashing Matthews' finding and his report remained valid.

She advised Shamy the council would release a public statement about the decision on Friday at 9am.

In a statement released with the letter from Baxendale, Swiggs said there was growing evidence the motive for the council's decision to investigate the complaints was political.

"This evidence may form part of the case I am considering lodging in the High Court."

Swiggs said it appeared to be media attention, 'not the complaints themselves, that spurred the council into action on this'.

A formal complaint was made to the council's acting chief executive Mary Richardson on September 4.

Mayor Lianne Dalziel told Stuff she was approached in May by members of a youth group about their concerns.

"I met with representatives of the youth group on 10 June 2019, where they described the pattern of behaviour and messages which they were concerned about."

Swiggs said Dalziel told the complainants the code of conduct was an extremely poor process for addressing such matters.

"The Council needs to be asked why they didn't then act to fix the Code of Conduct in June so it was fit for purpose and also why they later authorised what the Mayor says is 'an extremely poor process' being used in the middle of an election campaign."

The former councillor said the impact of the complaints had been "immense".

"It has been traumatising, it has changed my life completely and the process was flawed from the start."