The Information Commissioner's Office (ICO) has threatened Google with legal action unless all data gathered by Google Street View cars is deleted within 35 days.
The ICO first took action against Google in 2010 after it was discovered that the firm had gathered details such as email addresses and passwords of thousands of members of the public via its Street View cars.
Google said the aim of the project was to improve the geographic location database for its mobile applications by mapping WiFi networks, but received a massive backlash after it was discovered that personal details had also been taken without the awareness of individuals.
Following the reopening of the investigation last year, Google informed the ICO of the existence of more disks containing Street View data. In the latest development, the ICO has now warned Google that it could face legal action if all further data collated is deleted within a limited timeframe.
"Today's enforcement notice strengthens the action already taken by our office, placing a legal requirement on Google to delete the remaining payload data identified last year within the next 35 days and immediately inform the ICO if any further disks are found," said Stephen Eckersley, ICO Head of Enforcement.
"Failure to abide by the notice will be considered as contempt of court, which is a criminal offence."
Google has already provided assurances to the ICO that the data has not been accessed or entered into the public domain.
Eckersley added that companies like Google - which is already courting controversy with the development of its Google Glass devices - should do more to recognise data protection rules when implementing new technologies in the public domain.
"The early days of Google Street View should be seen as an example of what can go wrong if technology companies fail to understand how their products are using personal information," he said.
Google will also face enforcement actions from data protection authorities in a number of other EU nations, including France, Germany and Spain over the Street View breach.