The consumer watchdog is investigating whether customer reviews for "sharing economy" companies such as Uber and Airbnb are legitimate as part of an investigation into the sector.

The Australian Competition and Consumer Commission is teaming up with consumer agencies overseas to investigate whether online platforms are sufficiently managing customer reviews and not breaching the law.

Australian Consumer Law prohibits businesses from making or inducing false or misleading representations through testimonials. This includes testimonials on online review websites such as TripAdvisor and Zomato, as well as sharing platforms such as Kickstarter and Airtasker.

"The sharing economy is a fantastic development and offers a range of benefits for consumers and businesses," ACCC deputy chairwoman Delia Rickard said.