Royston Tesco car park: Ofcom says car key failure cause 'unlikely to be sinister'

Ofcom said the reason for the car fob failure was "unlikely to be sinister" and "certainly not alien phenomena"

A team investigating people being locked out of their vehicles when key fobs stopped working in a car park said the cause was likely to have been something "innocuous and accidental".

Police received about 100 reports of key fob failure in three days from people using the Tesco car park in Royston, Hertfordshire.

Communications watchdog Ofcom said the reason was "unlikely to be sinister".

It earlier found "no evidence of interference" in the radio spectrum.

Devices that can communicate wirelessly using radio waves, such as televisions, car key fobs, baby monitors, mobile phones and satellites all make use of specific areas of the radio spectrum.

Interference in this spectrum could affect the technology used to secure vehicles.

• Team finds 'no interference' as car keys fail

• Mystery as drivers locked out of cars at Tesco

• Car key jammers: What you need to know

On its website, Ofcom said it was "difficult to say what might have caused these particular issues" but in previous cases it had found the "culprits to be a faulty doorbell, and some retro lightbulbs".

"It it is likely to have been something fairly innocuous and accidental," it said.

"So, shoppers can rest assured that it was unlikely to be anything sinister behind the problem - and certainly not alien phenomena."

About 100 people had reported problems with their key fobs not being able to lock or unlock their vehicles

The agency earlier said its spectrum assurance team had checked the site for "signs of interference" and after finding none, had closed its investigation.

"We've advised the supermarket to keep an eye on this situation as it could potentially return, and if it does, they should get back in contact with us as soon as possible so we can carry out a further investigation if needed," the watchdog said.

PC Taranvir Gill, from Hertfordshire Police, who assisted with the Ofcom investigation into the mystery, said: "I appreciate this would have been a worrying time for those who were affected and I would like to thank them for their patience while this was investigated."

Tesco said it had been supporting the investigation.

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