The agent was dismissed from his job and surrendered his licence after the complaint.
He no longer works in the real estate industry and has indicated he intends to move away from the community he and his wife have lived in for more than 20 years.
The tribunal found the agent's actions were a gross invasion of privacy and a severe breach of trust. It cancelled his licence for six months, fined him $1500 and ordered him to pay $1000 in costs.
In a later decision, the tribunal granted the agent permanent name suppression - despite the fact his name had been published at the time of the complaint.
The Real Estate Agents Authority, which brought the case before the tribunal, alleged the agent had removed underwear and a bra from the drawer and held it in his hands. He then left the bedroom to talk to people attending the open home.
The agent later returned to the bedroom and again took lingerie out of the drawer and held it in his hands.
In a written submission to the tribunal, the agent denied the open home was still in progress at the time.
He said he had found the lingerie drawer open after the open home had ended and left the bedroom when he thought he heard a noise, not to talk to potential buyers.
"I looked in the drawer more out of curiosity and intrigue than out of malicious intent.
"It was a foolish thing to do and I regret it.
"The consequences of leaving things as I had found them may have been worse."
In a later decision on name suppression, the tribunal said it was conscious of the very heavy price the agent, and his wife in particular, had paid.
Neither the agent nor the vendor wanted to comment.
Canterbury University law expert Professor Ursula Cheer said when it came to name suppression, real estate agents arguably "get it a bit softer" than defendants in criminal cases.
"Arguably you could say that, if this had been decided under the ordinary law under the criminal justice procedure, an order like this might not have been made.
"It's interesting that once you make a change like that [to suppression rules], you might have tribunals like this that are out of step, basically."
Under the Real Estate Agents Act, name suppression can be granted if the tribunal believes it is in the interests of any person, including a complainant, as well as in the public interest.APNZ