Britain's broadcast regulator Ofcom has ruled that the ITV channel misled viewers by airing footage claimed to have been shot by the Irish Republican Army, which was actually material taken from a video game.

The video game material was used in the documentary titled 'Exposure: Gaddafi and the IRA' in September last.

The channel apologised after the issue came to light, saying it was "an unfortunate case of human error".

Ofcom today said it was a "significant breach of audience trust".

In the documentary, footage labelled "IRA Film 1988" was shown, described as film shot by the IRA of its members attempting to shoot down a British Army helicopter in June 1988.

But, the pictures were actually taken from a game called ArmA 2. Ofcom said in its ruling that it was "not sufficient for a broadcaster or programme maker to rely on footage provided by a third party source, on the basis that that source had previously supplied other broadcasters with archive footage".

It added: "We take into account that ITV: apologised; removed the programme from its catch-up video-on-demand service; and has now put in place various changes to its compliance procedures to ensure such incidents do not happen in future.

However, the viewers of this serious current affairs programme were misled as to the nature of the material they were watching."