Rook Matthews Sayer, whose acquisition by Connells Group was announced on March 1, was yesterday listing on all three major portals – Rightmove, Zoopla and OnTheMarket.

Another recent Connells acquisition, Paul Dubberley, was also yesterday listing on all three, in apparent contravention of OnTheMarket’s “one other portal rule”.

Last night, an OnTheMarket spokesperson said: “We are seeking clarification of the position from Paul Dubberley Estate Agents and Rook Matthews Sayer.”

Clive Rook, a former partner of Rook Matthews Sayer, had been on the board of Agents’ Mutual, appointed in March 2014. He stepped down in June 2015 after not seeking re-election. The reason stated by Agents’ Mutual was that he wished to concentrate on his own highly successful business.

Rook, for his part,  said at that time: “I have very much enjoyed being a part of the Agents’ Mutual board and my estate agency firm remains one of its biggest supporters. I take great satisfaction in what has been achieved so far and remain firmly confident about the prospects for the business.”

Rook retired from Rook Matthews Sayer on the sale in March to Connells of the company, which is based in Newcastle and has 17 branches in the north-east.

The firm has continued to trade under its own name and is headed up by managing director Janet Walker.

Paul Dubberley, the midlands firm acquired by Connells in May, was also advertising on all three portals yesterday, as it had been doing shortly after its acquisition.

Gascoigne Halman, confirmed by OnTheMarket to be the centre of a High Court hearing between Agents’ Mutual and Connells Group last week, was yesterday listing on Rightmove and OTM but apparently not on Zoopla.

EYE, which has screengrabs of yesterday’s triple portal listings, asked both OnTheMarket and Connells Group to comment. Connells Group said it was unable to do so.

Previously OnTheMarket has made it clearly that it will strictly enforce its ‘one other portal’ rule, meaning that agents who list on it must effectively choose between Rightmove and Zoopla.