A second major sponsor has cut ties with a property investors group that sent members a video that encouraged buyers to use fake names and target desperate families.
And the Commerce Commission has confirmed it is looking into the video amid concerns its contents "could be of concern under the laws we enforce".
"We will be seeking more information and considering the issues raised further before making a decision as to whether to investigate," a commission spokeswoman told the Herald.
Mitre 10 New Zealand Ltd has today issued the Auckland Property Investors Association (APIA) with notice to terminate its commercial partnership.
"The messages conveyed in the video distributed to APIA members were unacceptable to us," a spokeswoman said.
Earlier today the country's biggest bank terminated its sponsorship of the association after video footage emerged of Auckland property tycoon Ron Hoy Fong encouraging investors to target deceased estates, divorcees and "dummies" who don't know the value of their homes.
In a statement, ANZ's retail and business banking director, Antonia Watson, said: "We met with APIA this morning and advised them of our decision to terminate our sponsorship agreement.
"We have zero tolerance for being associated with people who recommend exploitation of individuals for their own benefit."
Meanwhile, APIA has today severed ties with Fong after apologising for the video and withdrawing it from its membership packs.
Association president Andrew Bruce issued a statement saying the group had terminated its commercial partnership with Fong and his Ronovationz property tutoring company.
The association also said it would assist with any Commerce Commission investigation into the video and its distribution, should such an inquiry take place.
"APIA is confident that the Commerce Commission will follow all due process to execute a proper investigation and to that end is prepared to assist and comply if required."
Fallout intensified today following revelations in Saturday's Weekend Herald that APIA had sent association members a video titled "How to make massive profit in today's property market".
In the video, Fong coached investors to look for the "seven Ds" - including deceased estates, divorcees, dummies and desperate families facing tight deadlines or mortgagee sales.
The tactics have being labelled appalling and exploitative, with claims Fong has been coaching investors to take advantage of vulnerable people.
Fong has denied the claims and said he would never try to deceive anyone.
While ANZ and Mitre 10 have cut ties with APIA, other sponsors are standing by the non profit organisation.
Maintain To Profit general manager Mark Trafford told the Herald the association had contacted the company over the weekend to explain the situation.
"We also understand that APIA have terminated the sponsorship of Ronovationz this morning. We have no say over that process but believe APIA are acting in the right way with integrity."
Trafford said it appeared that APIA management had not viewed the video before it was sent out to members and had agreed to change its processes before distributing video material.
"Based on this outcome, we will continue with our sponsorship and support of APIA."
Auckland's biggest realty firm Barfoot & Thompson is also standing by the investors group.
After reviewing its sponsorship over the weekend, Barfoot director Peter Thompson said today the firm would continue to sponsor the association after APIA officials apologised and immediately withdrew the video.
"They have been in contact with us over the weekend and explained their situation and processes they are following.
"It did not appear that they had viewed such video, and have agreed that their processes need to change when putting such videos onto [the] web."
Thompson said he understood APIA had reviewed its own commercial partnership with Fong.
"We have no say over that process but believe APIA are acting in the right way," Thompson said.
"For that reason, we will continue with our sponsorship with APIA."
The Herald has sought comment from other APIA sponsors and Fong has also been approached for comment.
His video also advised investors to give vendors fake names when making repeat offers on the same property, and getting investor groups to work in packs by putting in multiple low-ball offers on a property in a bid to drive down the price.
Labour's Consumer Affairs spokesman Michael Wood has written to the Commerce Commission calling for an urgent investigation into the material, which he said was potentially illegal under the Fair Trading Act.
He has also asked the commission to issue a statement condemning the tactics advocated in the video and to use its powers to compel Fong and APIA to give evidence in any inquiry.
"Regardless of the outcome of a legal complaint, anyone with a sense of decency can see that this behaviour is outrageous and unethical."
He welcomed news of ANZ pulling its sponsorship today.
"Good that ANZ have shown some leadership. Would have thought the other sponsors and Minister may have acted a bit more quickly."
Asked if she backed a Commerce Commission investigation into the video, Consumer Affairs Minister Jacqui Dean said: "It would be inappropriate for the minister to direct the Commerce Commission as an independent Crown entity."
Labour's housing spokesman Phil Twyford said it was good that ANZ had taken a zero tolerance approach "to this kind of rat bag activity".
"It's a shame the minister does not act so proactively and promptly on such clear principles."