The Information Commissioner's Office said it would not investigate Google over the recent revelation that its Street View cars have been mistakenly collecting data from unsecured Wi-Fi networks for three years.

The search engine's error came to light after the German data protection authority audited the Wi-Fi data collected by Street View cars for use in location-based products such as Google Maps for mobile.

The authority revealed that as well as collecting SSID information (the network's name) and MAC addresses (the number given to Wi-Fi devices such as a router), Google had also been collecting payload data such as emails or web page content being viewed.

The Information Commissioner's Office (ICO) told the Financial Times that despite the fact Google could possibly have broken the UK Data Protection Act, "the commissioner would not be taking further action against the company" after the search engine assured the organisation it would delete the data "as soon as reasonably possible".

However, German commissioner for data protection, Peter Schaar, said a "detailed probe" into the incident should take place as he though Google's explanation on how the error occurred was "highly unusual".

"One of the largest companies in the world, the market leader on the internet, simply disobeyed normal rules in the development and usage of software," Schaar told the Financial Times.

The US Federal Trade Commission is also expected to investigate the matter.

See also: Google gets 1,116 UK gov't requests for user data