The threat of cyber attack loomed over the opening ceremony for the London Olympics last year, officials have revealed - and was thought so realistic that officials put back-up systems in place so the lights could be turned back on in 30 seconds the case of an attack on the electrical grid.

Oliver Hoare, head of cyber security at the London 2012 Olympics, was woken at 4.45am on the day of the opening ceremony by a phone call from intelligence agency GCHQ (Government Communications Headquarters), he revealed in an interview with Radio 4.

"There was a suggestion that there was a credible attack on the electricity infrastructure supporting the Games," Hoare said. "And the first reaction to that is, 'Goodness, you know, let's make a strong cup of coffee.'"

A meeting of senior Government defense officials was held that day in London’s Cabinet Office. Technicians initiated a “back-up” plan where the lights could be switched back on in 30 seconds.

"The clock was absolutely ticking," said Mr Hoare. "We effectively switched to manual, or had the facility to switch to manual. It's a very crude way of describing it. But effectively we had lots of technicians stationed at various points.”

ESET Senior Research Fellow David Harley says that businesses can learn from this level of contingency planning.

“The nature of the threat in these reports isn’t entirely clear, or how much substance there was behind those fears of a direct attack on UK power utilities or the Olympic Games in general, but the business world in general might learn something about risk assessment and contingency planning from this report,” Harley says.

 “Although the same manpower and intelligence-gathering resources obviously aren’t available to most businesses, the simple measures of ensuring a process is in place in the event of a suspected breach can easily be replicated. Employing staff whose responsibility it is to ensure adequate cyber security is in place across the business, regularly monitored and updated with a plan in place to protect core assets should be a consideration for even the smallest businesses.”