Karen Price issued a statement following reports this morning that she was behind the @TarnBabe67 account, admitting she was responsible.
She confirmed she set up the account in the weekend "after a period of intense media attention and scrutiny of our family'' and apologised.
"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.''
She said she had "made a number of comments that I deeply regret''.
Ms Price also said her husband had no knowledge of the Twitter account until he was asked about it by media last 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.''
The account, which was reportedly set up on September 26, attacked Mr Cunliffe's rival Grant Robertson and MPs Trevor Mallard and Clayton Cosgrove.
Mr Cunliffe was @TarnBabe67's first follower, according to other Twitter users.
Comment was being sought this morning from both Ms Price and Mr Cunliffe.
Twitter users said Mr Cunliffe was one of only seven followers the account had over the weekend.
"Interesting he knew nothing about a 3 day old account when he was one of only 7 followers.....,'' one posted this morning.
Mr Cunliffe told Fairfax last night that he did not know about the account and it had ``nothing to do with my campaign''.
The @TarnBabe67 account took aim at Mr Cunliffe's critics, hitting out at the Weekend Herald for running candid photographs of Mr Cunliffe deep in thought on a beach near his Herne Bay home, and went on to criticise others in the media.
Tweets also hit out at Labour members in the 'anyone but Cunliffe' faction of the party, slamming Mr Robertson, and branding Mr Mallard and Mr Cosgrove "long past their use-by date''.
"The jealousy of Cosgrove and Mallard knows no bounds,'' @TarnBabe67 reportedly posted.
Ms Price is reportedly known by the nickname 'Tarn', which was apparently what alerted Labour Party members to the Twitter user's true identity, Fairfax reported.
Mr Cunliffe said last night: "My understanding is that it was started by a family member who wanted to defend me at a stressful time. The Twitter account was activated in September 26 and has been closed down.''
David Parker told TV3's Firstline today he received a call from Mr Cunliffe last night apologising for the Twitter account.
"It is a time of high emotion for families, David worked hard over the campaign and his family will have seen the pressure that he's been under and how much he's done to try to win for the Labour Party, so they'll be feeling bruised for him and I'm sure that she regrets her actions,'' Mr Parker said.
Mr Cosgrove told RadioLive the tweets were "sad''.
"There is a code of conduct which the party has which basically says we should treat people with respect and I don't think that family members should be used in this way,'' he told the station.
Speaking to NewstalkZB, Mr Cosgrove said if his partner opened a Twitter account to attack caucus colleagues he would know about it.
He also said he was not jealous of Mr Cunliffe, as the Twitter posts had reportedly suggested.
"No I'm not jealous of Mr Cunliffe. I'm certainly not jealous of a 24 per cent election result which is the worst result the Labour Party's had since 1922,'' he told Newstalk ZB.
"I think it's sad that he would use his wife to attack caucus colleagues.''
