Adams was once the golden girl of Bayleys, making millions in commission and becoming the company's top seller. She left abruptly last March and weeks later started work with Sotheby's International.
The Sotheby's website says she "has sold over 700,000,000 dollars of premium real estate, consistently marking her out as one of the leading realtors in New Zealand".
Questions about her behaviour at Bayleys were raised in January last year after she sold a home in Palmer Cres, Mission Bay.
Adams had been listing and selling agent for the property, which has four bedrooms and a large family room overlooking a private pool surrounded by lush gardens.
Bank records show she lent buyer Geoff Harriman $187,250 to ensure the sale went through in September 2010 for $1.7 million. They were subsequently registered as owners, with the JMAR Trust - of which Adams was a trustee. The property was renovated and sold a year ago for $2.1 million.
Bayleys director Michael Bayley told yesterday's hearing that on a standard form asking whether she had anything to declare about the sale, Adams circled "No".
When called into a meeting last February, she initially denied any involvement, Mr Bayley said. "She continued to talk in a roundabout manner and say she was not involved."
But later in the meeting she admitted her involvement, he said.
Bayleys terminated her contract and, as legally required, advised the agents authority of the company's concerns.
The authority's complaints assessment committee found her guilty of professional misconduct. Adams had denied the allegation.
The committee referred the matter to the tribunal because of the seriousness of the allegations.
Prosecutor Brent Stanaway told the hearing Adams made the loan to Mr Harrington in two transactions she said were "acts of friendship".
The authority alleges Adams and Mr Harriman "discussed the property and renovation plans" at the time of the auction.
Mr Stanaway said notes from Adams' banker, Martin Farrell, indicated the pair planned to "put $100k into [the property] and try to sell it for over $2m ... for a quick profit".
Mr Farrell also said Adams told him it was important she "was seen to be kept at arm's length for the purchase of the property".
Through her lawyer, John Billington QC, Adams admitted her conduct was unsatisfactory, but disputed it was wilful or reckless.
He said she made an "unintentional mistake, albeit for the right reasons, to conclude a transaction in the best interests of both vendor and purchaser."
She had no plans to get involved in the sale and didn't lend Mr Harriman the money until it had gone unconditional, the QC said.
The hearing was due to last three days but proceedings were adjourned unexpectedly yesterday afternoon.
It is understood negotiations between representatives of Adams, Bayleys and the authority took place in chambers.
High end homes and a fugitive brother
A fugitive brother and multimillionaire clients are part of Marnie Adams' colourful past.
During her eight years at Bayleys, she mixed with Auckland's business and corporate elite, specialising in high-end homes in Remuera and the eastern bays.
Among the properties she sold was a castle-like estate in Mission Bay's Godden Cres that went for $10m in August 2010.
An architecturally designed St Marys Bay home sold for $3m in 2008. A year earlier, she got $6m for a four-bedroom property dating to the early 1900s in Remuera's Victoria Ave.
Adams was once the company's top seller and three times its top residential seller.
Her family have also been in the headlines, with brother Danny Butler arriving in New Zealand in 1991 on the run from British police.
He had been sentenced to 18 months' jail for possession of ammunition. But after being freed on bail, pending an appeal, he boarded a plane for Auckland. It is understood he spent 6 years here. He applied for refugee status on the grounds he would be shot if he was deported back to Ireland but officials rejected his case.
Other real estate agents who've courted controversy:
Hearings reveal bitter real estate scraps
Harcourts' online ad ruled misleading
Northland real estate agents penalised
Real estate agent censured for abusive email
Christchurch realtor slapped with heavy fine
Real estate agent advertised orchard without owner's consent