Zoopla has confirmed that it does make direct contact with sellers and landlords.

It said this is part of its consumer awareness campaign.

The issue was raised in a post on Friday, and also in an interview Eye did with Robert Sargent, group chief executive of Acorn (see today’s separate story).

Sargent said he was very concerned after hearing that the owner of a property no longer displayed on Zoopla but still listed on Rightmove had been contacted by Zoopla.

The post on an Eye story on Friday also expressed concern.

It read: “I saw this week a letter sent to the addresses of the properties that an agent had withdrawn from them when they stopped advertising on Z.

“The letter said it was disappointed to see the property had been withdrawn from their portal and suggested that the owners were missing out on huge interest in their property as a result.

“This, added to billboards I saw today from Z saying ‘Smart is committed to getting the best price for your home, ensure your agent uses Zoopla’ – gloves are off and it’s dirty tricks time.”

We invited Zoopla to comment, and a spokesperson said: “We have a very broad consumer marketing campaign which communicates the benefits of Zoopla and the other brands that we own and power to consumers across the UK in various ways.

“Part of this campaign includes direct mailings from time to time to vendors and landlords whose properties are not on our platform to make them aware of the audience they are potentially missing out on, given the fact that two thirds of all house hunters in the UK search via our platform and around half of those use our sites exclusively every month.

“Data used in these campaigns is sourced externally and this is a natural part of our consumer awareness campaign.”