Mairs was photographed leaving the property on the morning of the auction in February 2017 after the owner's mother noticed someone had been sleeping in one of the bedrooms.
As Mairs was leaving, he claimed he was due to show someone around the property that morning, before he returned to grab his things from the apartment and left the keys on a wall.
The woman phoned police, according to an earlier Real Estate Agents Disciplinary Tribunal judgment, who found Mairs outside a cinema at the Mission Bay shops.
Mairs later claimed the agent in charge of the Mission Bay property, David Anderson, had given him the apartment's keys the previous night and allowed him to sleep in it.
But Anderson denied this, saying he had been home with his wife.
The next morning, Anderson said he received two missed calls and four texts, according to the judgment:
Mairs: The parents are here. Wt do I say
Do I just grab my stuff and run
I'm in the bathroom hiding
Do you reckon I could say I know the owners or something. Or run?
Anderson: What are you talking about? What property
Mairs: Yeah you don't want to tell them I was just getting changed before I show a client through
Anderson: Are you f***ing joking? You'd better not be in the property I'm listing.
Mairs: I've shot thru. But they were on my tail and I'm trying to get a taxi outta here, but it is difficult with no credit. Can you please call a taxi to the Berkely cinema. I just grab the key off ur desk and was getting changed before I show a buyer through
Sorry about this. I'll have to find you a buyer for it by tomorrow. So send me details.
Sorry. Hopefully Matt doesn't find out. I'll be fired if he does no doubt.
Anderson: Let me know when you can talk. I need to get to the bottom of this
Mairs: just got out of cells. Sorry bud. I had Ben Turner meeting me at 12 PM. I'm going into Federal Street detox unit … And I quit Bayleys.
The tribunal found Mairs guilty of disgraceful conduct, concluding that Mairs accessed the property "for his private advantage and in a way which was plainly un-authorised".
"This was serious misconduct which in our view would be regarded by reasonable agents of good standing and members of the public as being disgraceful."
The new ruling, which stripped Mairs of his licence, says an aggravating factor was how long he spent in the house.
"It was not just a matter of entering the property briefly: he stayed the night and used the bed and bathroom," the judgment says.
Mairs' bid to have the ruling kept secret - on the grounds it would be damaging to his future work prospects - was also thrown out.
Bayleys group licensee Tony Bayley told the Herald today that from the outset the agency had fully and openly cooperated with the REA's investigation into Mair's behaviour, and supported any actions the regulatory body deemed appropriate.
In May, Bayley said in a statement the company contacted the property owner the moment it heard of Mairs' "inappropriate behaviour".
The company "took all steps possible to remedy Mairs' indiscretion, then immediately notified the REA [Real Estate Authority] of the incident".
Mairs' resigned from the agency immediately.
