Google has removed a fraudulent anti-virus mobile app from its Play store after a blog revealed it did nothing.

Virus Shield, developed by Deviant Solutions, was launched at the end of March for $3.99, promising to prevent harmful apps being installed, scan device data in real time and protect personal information.

The app was downloaded more than 10,000 times before Android Police’s Michael Crider posted the decompiled code online, demonstrating that its only function was to change art with a cross on it to a similar design with a tick.

Writing on the site, he said: "It’s somewhat disheartening that an app so obviously fake could rise to the top, especially considering that it’s paid, and possibly hundreds or thousands of people have been defrauded already."

He added that the episode highlights the dangers of the Play store’s open contributing policy, which provides minimal entry barriers for potential developers.

Developer accounts are subject to a single $25 registration fee, and those planning to monetise apps must be working from an approved country, most of which are in the developed world.

Google retains the power to remove inappropriate apps from the store, and users can flag apps for sexual, violent or hateful material, but there is no prior vetting of apps, meaning that users have to rely on reviews from early adopters.

Virus Shield was rated 884 times before it was pulled, with an aggregate score of 4.5 stars.