– Oliver Hoare, London 2012 head of cyber security
"There was a suggestion that there was a credible attack on the electricity infrastructure supporting the Games.
The clock was absolutely ticking.
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."
Security experts have revealed that they received suggestions of a cyber attack targeted at the opening ceremony of last summer's Olympic Games.
Oliver Hoare, head of cyber security for the Games, told the BBC he received a phone call from government listening post GCHQ on the day of the opening ceremony.
There were concerns that the lights in the Olympic stadium could have been turned off during the ceremony.
The threat failed to materialise and the ceremony went off without a hitch, but security officials revealed that they had put extensive precautions in place to withstand such an attack.
Mr Hoare said he" twitched" every time the lights in the stadium dimmed as he watched the ceremony at home with his family.