The EU has ordered Google to delete images captured for its Street View service after six months.
The images are captured by specially adapted Google Street View cars that travel the UK taking photographs. However, the service has attracted a number of privacy concerns.
Currently, Google holds Street View images for a year but the EU's Article 29 Data Protection Working Party has said the search engine must chop this in half, as 12 months is a "disproportionate" length of time.
The working party said in a letter to Google, which was obtained by Bloomberg, it was "concerned that Street View continues to give rise to data-protection issues," despite the fact the search engine met its initial requirements.
"In Europe, we have high standards for data protection. I expect that all companies play according to the rules of the game," said EU justice commissioner Viviane Reding.
The working party also told Google to offer Brits more information regarding when its Street View cars would be photographing their area.
"Google needs to raise much more awareness of Street View cars going though people's streets as there is an option to opt out of appearing in them but no one knows about it," said the Commissioner's office.
Google lawyer Peter Fleischer defended the search engine's year-long retention period.
"The need to retain the unblurred images is legitimate and justified - to ensure the quality and accuracy of our maps, to improve our ability to rectify mistakes in blurring, as well as to use the data we have collected to build better maps products for our users," he said.
"We have publicly committed to a retention period of 12 months from the date on which images are published on Street View, and this is the period which we will continue to meet globally."