An electrical and plumbing business has been fined $125,000 for a "sophisticated and well-planned" scheme using fake reviews of its services to mislead consumers.

The Commissioner for Consumer Affairs began legal action against Star Plus Group Pty Ltd and a related business SPG(SA) Pty Ltd in the Federal Court for breaches of the Australian Consumer law, accusing the companies of engaging in misleading and deceptive conduct.

The Federal Court was told that between 2017 and 2019, Star Plus posted 126 fake reviews to the Yellow Pages website, with a further 16 fake reviews and nine fake proofs of purchase submitted to the Product Review website. SPG later posted six fake reviews and one fake proof of purchase document to the Proudct Review website.

Both companies then used the fake Yellow Pages reviews to advertise on the Star Plus Group website that it had a rating of 4.8 out of five stars.

"In this day and age, consumers often rely on seemingly independent websites and online reviews when choosing a service," Acting Commissioner for Consumer Affairs Fraser Stroud said.

"This business undertook a coordinated and sophisticated campaign designed to deceive consumers, creating fake consumers and - in the case of the Product Review website - developed dummied up invoices for their non-existent customers.

"In posting the fake reviews, a VPN would mask the source's location, demonstrating just how far the business was prepared to go to keep up this pretence."

Justice Shawn McElwaine found the conduct "was deliberate, was sophisticated and well-planned", noting that "this type of conduct is corrosive of fair competition, insidious and likely difficult to detect."

He fined SPG(SA) Pty Ltd a total of $125,000 and ordered the company to publish a notice on the Star Plus Group website acknowledging its conduct, the Court's finding and the fine.