Labour leadership candidate David Cunliffe had no knowledge of a Twitter account set up by his wife, Karen Price, in which she criticised members of his caucus, he says.
Ms Price confirmed in a statement this morning that she had set up the anonymous account at the weekend in an "ill-judged" action.
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Mr Cunliffe formally resigned as Labour Party leader yesterday following the party's dismal election result and is seeking re-election. Senior MP Grant Robertson is also a candidate for the top job.
Karen Price and David Cunliffe on election day. Photo: REUTERS
This morning Ms Price issued a statement saying she deeply regretted comments she made in the anonymous Twitter account.
"After a period of intense media attention and scrutiny of our family, I set up and used an anonymous Twitter account over the weekend and made a number of comments that I deeply regret," the statement said.
"Our family has been under intense media pressure since the election. My actions were ill-judged and were the result of extreme frustration and trying to look after my husband and family.
"David had absolutely no knowledge of the account until a media outlet raised it with him on Tuesday night.
"The account is now closed and I apologise to all those I have offended in any way. I will be taking a short break and will not be commenting further."
Mr Cunliffe said he knew nothing about the account until it was raised with him by a reporter and wants to convey his apologies to the MPs referred to in his wife's tweets.
"I've rung and left messages of apology to almost all of them. I've got one, I think, still to track down.
"I want to convey to them face to face ... that it is deeply regretted and there was no knowledge of it."
He said his wife acted to defend him because she felt he had come under attack at at time of considerable stress.
Labour MP Clayton Cosgrove. Photo: Supplied
Ms Price reportedly tweeted of Labour MPs that "the jealousy of Clayton Cosgrove and Trevor Mallard knows no bounds"; they were past their use-by-date; and that the first person to be disloyal to her husband should be expelled from the Labour Party.
Mr Cosgrove said attacks on caucus colleagues through blogs and Twitter was symptomatic of Mr Cunliffe's leadership, and said comments about envy were wide of the mark.
"Well, why would I be jealous of a guy who's just led us to the biggest catastrophic defeat since 1922?
"Secondly, David and I came into politics at the same time. I'm 44. I know God has endowed me with the looks of a 64-year-old - there's little I can do about that. He is 53, I am 44."
Ms Price's admission and apology comes a day after Labour acting deputy leader Annette King said the party wanted to keep its leadership contest seemly.
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Acting leader David Parker said this morning he still hoped it will be a clean contest despite the Twitter controversy.
"Look I don't like that sort of thing ... I want us to rise above that sort of thing in politics, I think most people do," he told Morning Report.
"I can't control the actions of individuals but I know that both myself and Annette King will be doing our best to keep it seemly."