The International Maritime Organization has drawn up a list of tactics to tackle the threat posed by a corrupt insider or a seafarer with a grudge.

The global shipping regulator has published a 12-page guide on measures to put in place from surveillance systems to patrols to limit the opportunities for terrorists and criminals.

The suggestions have been developed using the expertise of aviation regulators to deal with the threat from insiders, whether acting through maliciousness, complacency or ignorance.

Criminals routinely tap insiders to exploit vulnerabilities in systems and to use their access to break into protected areas.

European police agency Europol warned last year of the growing use of so-called PIN code fraud, where gangs pay off corrupt insiders to secure the unique computerised details of containers.

They are then able to load the chosen container with drugs and redirect it to fellow gang members who can retrieve the cargo outside of the ports.

The IMO has produced what it calls an insider threat tool kit. It includes suggestions to improve security through enhanced background checks, entry screening to sensitive areas and training to pick up on tell-tale behaviour of infiltrators.

Andrew Clarke, technical officer at the maritime security section at the IMO, said: “We currently face an extremely diverse and challenging set of maritime security threats and risks globally.

“It is crucial to keep developing new products and training in an evolving world.”