Google is pledging to crack down on fake online reviews with tougher punishments for rogue reviewers and businesses after an investigation by regulators in Britain.

The UK has reached an agreement with Google to counter fake reviews, with the internet giant committing to several remedies.

Britain's competition regulator said on Friday it had secured important changes from Google to tackle fake reviews, including to sanction UK businesses that have boosted their star ratings with fake or misleading reviews.

Google has committed to cracking down on fake reviews by improving fraud detection and punishing offenders. Businesses using shady tactics will lose the ability to submit reviews or have existing ones wiped for at least six months.