Sometimes the customer isn't always right, especially when it comes to leaving fake reviews.

A Melbourne dental surgeon who claimed an anonymous person left a scathing and defamatory review about his business on Google has won the right to have the reviewer’s identity revealed.

Dr Matthew Kabbabe, who operates out of his clinic in Northcote, just north of the Melbourne CBD, took the matter to the Federal Court requesting Google reveal the person’s identity.

He said a user calling themselves “CBsm 23” left the only negative review about his business.

On Wednesday, federal court justice Bernard Murphy granted Dr Kabbabe’s request.

“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.