The search has included specialist officers from the Northumbria Police's Marine Section, the National Police Air Service, drones and dog handlers.

He told the BBC at the time a Sunday air service offered him a chance to balance working away from home and getting back to spend quality time with his family.

They have been supported by other agencies and emergency services, such as the fire and ambulance service, National Police Air Service, and RNLI.

The force said drones and the national police air service were sweeping the area to monitor those involved.

McBride’s documents formed the basis of an Australian Broadcasting Corp. seven-part television series in 2017 that contained war crime allegations including Australian Special Air Service Regiment soldiers killing unarmed Afghan men and children in 2013.