Britain’s information watchdog says Google appears to have breached an agreement to delete data collected by its StreetView vehicles.

The Information Commissioner’s Office said Friday it had received a letter from Google Inc. saying the Internet search leader still possessed some of the data collected by its StreetView vehicles prior to May 2010. It said the data should have been deleted by December 2010.

Google’s failure to delete the data as promised is “cause for concern,” and the existence of the data appears to breach an agreement signed by the company in 2010, the ICO said in a statement.

Google has come under fire after vans collecting data for its StreetView application also scooped up sensitive information from unprotected wireless networks.