Ford Europe has increased the number of models offering owners heightened protection from theft thanks to security technology which disables their keyless entry fobs when not in use to block illegal hacking.

The feature is now standard for the Romanian built Puma crossover plus the Kuga SUV. The upcoming US made Mustang Mach-E EV will also benefit.

All Puma production now includes the motion-sensor key fobs. Electrified Kuga models gained the deterrent in July last year.

In 2019, the fob with sleep mode was introduced for the Fiesta and Focus.

Data from security analysts Retainagroup shows thefts of the latest Fiesta, which introduced the smart fobs two years ago, have fallen by two-thirds compared with the number of previous Fiestas stolen.

Keyless entry fobs of all makes of cars have been targeted by thieves with 'relay box' equipment, used to extend the signal from fobs in homes to unlock and start vehicles parked outside.

A motion sensor inside the Ford fobs detects when it has been stationary for longer than 40 seconds and triggers a sleep mode which will not respond to attempts to hack its signal via a relay box or through the misuse of other specialist equipment.

Moving the keyless fob by picking it up inside the home and taking it to the car will restore full functionality by the time drivers approach their cars, the automaker said. The Ford fobs also are designed to operate only within a 2m radius of the cars they are bonded to.

Simon Hurr, Ford security specialist, said: "The online availability of devices, which have no place in public hands, has long been a problem. We are pleased to extend our simple but effective solution, to help protect more owners of our most popular cars."

Existing models can have security upgraded with replacement sleep-mode fobs, priced in the UK between GBP74 and GBP94 for Fiesta and Focus, plus 0.9 hours labour to programme and test. This is available to owners of the Fiesta on sale since 2017 and Focus from 2018.