HACKERS can remotely switch off a car engine and cause drivers to swerve, a cyber security expert has warned.

Professor Mark West from tech firm Roke made the stark warning to hundreds of cyber industry insiders at the quarterly Cynam event on Thursday night in Cheltenham.

The sold-out conference took place a stone’s throw from GCHQ, the government’s eavesdropping hub.

The so-called “doughnut” has spawned a booming cyber industry in the west of England, with tech start-ups offering potential recruits perks such as “food, booze, massages and yoga.”

Mr West said his company had found vulnerabilities in car bluetooth systems and other onboard gizmos that hackers can exploit to wipe transmission boards or modify speed readouts, which will scramble power-steering systems.

He told the audience to “go and have a play with a car” using a Raspberry Pi, the mini computer used by programmers.

Another industry speaker, David Balson from Ripjar, warned about the perils of state-sponsored cyber attacks.

However, the regional cyber co-ordinator at South West Police said in his experience the most prolific hackers were teenage boys.

“They will attempt absolutely anything,” Detective Sergeant Jon Atkin said.

He described one case where 15-year-olds hacked their school IT network to modify exam results using an “RAT” (Remote Access Trojan), a stunt that saw them convicted of cyber crime offences.

Other hackers had used the same RAT for voyeurism offences, Mr Aitkin said.

The event also saw a speaker from GCHQ step out of the shadows to describe his agency’s work tackling child sexual exploitation.

Known only as “Del,” he said they worked closely with the National Crime Agency to hunt paedophiles online.

“What we are seeing if anything is how big this problem is,” Del commented, saying that “80,000 people in Britain represented a sexual threat to children.”

The scale of the challenge has seen the spy agency work with child protection charities like the NSPCC to share information.

“This is not normal for GCHQ to establish dialogue,” Del said.

The event closed with a session by software engineers from BAE Systems Applied Intelligence.

They showed the audience how to tap an ethernet cable, using tools costing as little as 70p, to bug a conversation.