The British newspaper The Sunday Mirror warned of a potential “risk to national security” after a USB containing sensitive information about Heathrow airport was reportedly found in the street.

More than 174 documents were said to be on the unencrypted USB drive, including some marked as “restricted” or “confidential” detailing the precise route used by the Queen when she uses the airport, and security measures in place to protect government ministers and foreign dignitaries.

Other information allegedly contained on the device included details of:

• the types of ID required to access restricted areas.
• the location of CCTV cameras, and a network of tunnels and escape shafts linked to the Heathrow Express.
• timetables followed by security patrols to guard against terror attacks and suicide bombers.
• the ultrasound radar system used to scan the airport’s perimeter fence and runways.