British telly outfit ITV has admitted that it tried to palm off footage from a computer game as real in a documentary investigating links in the 1980s between former Libyan leader Muammar Gaddafi and the IRA.

The documentary claimed it showed genuine scenes of the Irish terrorist group downing a British helicopter. "With Gaddafi's heavy machine guns, it was possible to shoot down a helicopter – as the terrorists' own footage shows," warns a voiceover in sombre tone. "No one died in the attack," he reassured viewers. At least he was right about that.

What went wrong was that ITV had archive footage from both the real incident and the video game and it is understood the wrong clip was mistakenly used during the editing process. The footage actually came from a video game, called ArmA 2, is set in a fictional post-Soviet country called Chernarus, where a Western- backed democratic government is trying to hold on to power from communist rebels. We guess it was just too realistic.

ITV has said the documentary will be re-edited for all future broadcasts.