Sometimes the customer isn't always right, especially when it comes to leaving fake reviews. In a landmark ruling, an Australian court has granted a Melbourne dentist an order which forces tech giant Google to reveal the identification of an anonymous online reviewer.

The lawyer for Dr Matthew Kabbabe who received an anonymous online negative review has welcomed the decision by an Australian Federal Court judge compelling Google to release the identity of the reviewer, including any names, phone numbers, IP addresses and location metadata.

Dr Kabbabe claims the reputation of his Melbourne dental practice has suffered, following a scathing review left by a disgruntled customer late last year.

Dr Kabbabe launched court proceedings in the pursuit of unmasking the unknown customer, who operated under the pseudonym "CBsm 23" so that he can bring a defamation proceeding against him or her.

In giving his order, Justice Bernard Murphy noted the dentist relies on the internet to generate business.

“Dr Kabbabe seeks preliminary discovery to identify the unknown prospective respondent so that he may bring a defamation proceeding against him or her,” Justice Murphy wrote in his ruling.

“For the reasons I explain, I consider it appropriate to accede to the application and to grant leave to Dr Kabbabe to serve the proceeding on Google in the USA … by sending it by international registered post, with an acknowledgment of receipt to be provided to Dr Kabbabe’s solicitor.”

Dr Kabbabe’s lawyer, Mark Stanarevic, told the ABC the ruling is “groundbreaking” and a win for his client.

“A bad review can shut down a business these days because most people live and breathe online,” he said. “Sometimes people just look at one or two bad reviews and decide to go somewhere else. We think Google has a duty of care to Australian small businesses and businesses globally for allowing these reviews to go on.”

Mr Stanarevic said it was unfair for people to leave negative comments while hiding behind pseudonyms.

Dr Kabbabe’s case will return to court on March 25.