The Commerce Commission has confirmed it is investigating real estate agents boycotting Trade Me.
Commission spokesman Gordon Irving said the situation with the real estate ads was of interest to the organisation.
"I can confirm the commission is investigating this issue. It is too early to determine the possible outcome of the investigation," he said.
Market analysts had previously raised the issue, saying real estate is a major source of revenue for Trade Me so the boycott would negatively affect the business.
The Herald has reported that a group of real estate agents said they would boycott Trade Me after the company announced price rises.