Two of Australia's best-known real estate websites have crossed swords after one ran an advertising campaign claiming to be the biggest and best in the country.

REA Group Limited, which owns and operates www.realestate.com.au, claimed its competitor Domain, owned by Fairfax Media, engaged in misleading or deceptive conduct with ads claiming to have more property listings and to be more highly rated. The campaign in question began in February 2016 across Victoria, NSW and Queensland, with…