John Palino met Len Brown's former mistress for a late-night discussion in a Mission Bay car park the night after the mayoral election and just two days before the affair was made public.
Bevan Chuang claims Mr Palino's camp raised the possibility that Mr Brown could be shamed into resigning the mayoralty.
When news of the scandal broke on Tuesday, Mr Palino denied any knowledge of the affair. But he met Ms Chuang on Sunday, October 13 - the day after the election.
The meeting, arranged by text message, happened shortly before 10pm in the carpark across from the Berkeley Cinema.
Ms Chuang told the Weekend Herald the meeting was to discuss whether Mr Brown might resign over the affair.
Last night, Mr Palino's campaign manager, John Slater, confirmed a meeting had taken place, but said it was just a "general chit-chat".
However, Ms Chuang claims she and Mr Palino discussed revealing to Mr Brown information about the affair and whether he might resign, claiming poor health.
(He suffered a major heart attack in May 2008.)
"This would give him an opportunity to be a hero and assured that ... he did not lose any face, and yet allow him to move on to bigger and better political agendas," she said.
Mr Palino told Ms Chuang he did not believe a story would be published, she claimed.
She said they parted ways at around 11.30pm.
"John Palino and I walked towards his car and [he] indicated that we cannot be seen together," she said.
In a statement to the Weekend Herald, the 32-year-old said she had met Mr Palino several times. They also met at the Espresso Workshop in Epsom on May 15 and at his campaign office in Ponsonby two weeks later.
Mr Palino has previously confirmed he met Ms Chuang during the election campaign, but when asked on Tuesday what he knew about the affair, he said he had no knowledge of it and that he did not know who was involved.
However, in her statement, Ms Chuang said that last Sunday afternoon, Mr Palino called her from a phone belonging to his fiancee, Rose Li, to ask if Ms Chuang was OK.
Later that afternoon, he sent a series of texts from his own phone to organise the meeting.
Mr Palino, who is in Melbourne, did not return calls last night.
The message on his phone said he was overseas, celebrating Ms Li's birthday "finally" and taking a break.
Mr Slater said he was told on Monday that Ms Chuang had requested the Mission Bay meeting.
"And I spoke to John briefly about it, and there wasn't a lot of discussion, because it wasn't until the situation blew on Tuesday that I realised the full significance of it."
Asked whether he and Mr Palino discussed the affair, he said: "We didn't go into it in any detail."
Asked whether the Mission Bay meeting was about how to use the affair to try to get Mr Brown to agree to step down, he said: "I've got no knowledge about that at all. And as I say I spoke to [Mr Palino] as recently as 6pm [last night]... and he just said it was general chit-chat."
Mr Brown, who has been holed up behind closed doors at the Auckland Town Hall since Wednesday, will on Monday make his first public appearance since the scandal broke.
After cancelling several attendances at public events, including the Prime Minister's Olympic Gala Dinner on Thursday, he is due to attend the Fonterra Milk for Schools programme at Three Kings School.
Prime Minister John Key met Mr Brown at his office in the Town Hall yesterday for one of their regular catch-ups. Said Mr Key: "We pretty much stuck to business."
The Rev Uesifili Unasa, who ran as a candidate against Mr Brown, said he was still a big supporter of his and met with him on Thursday to offer his backing and pastoral advice.
"I still love Len. I gave him a hug and we sat down ... It was very emotional and even I began to cry.
"It's a really sad thing for everybody - whether you agree with him or not.
"He's a good person and I respect him for that and that hasn't changed for me. I don't judge him on what he's done."
Asked how he thought Mr Brown felt to be contacted by him, Mr Unasa said: "I think he was relieved."
Mr Brown also denied claims by Ms Chuang that some hotels rooms he booked for the pair were offered free of charge.
In a written statement to the Weekend Herald, the mayor's head of communications, Dan Lambert, said: "He was not offered, or has accepted, free hotel stays in connection to the relationship and paid the standard rate out of his own pocket.
"Any expenses he incurred in connection with this relationship, he has paid for out of his own pocket."
- additional reporting: Moana Tapaleao