There is a scene in the 1996 action movie The Rock when scientist Stanley Goodspeed – played by Nicolas Cage – describes what would happen if a glass-encased chemical he is trying to deactivate is used on humans.

Your muscles freeze, you cant breathe, you spasm so hard you break your own back and spit your guts out. But thats after your skin melts off, he says.

The dialogue – grim though it sounds – is typical Hollywood spiel in a movie that sees Goodspeed team up with an ex-con (Sean Connery) to stop renegade general (Ed Harris) from launching a chemical attack from Alcatraz against San Francisco.

Described by Variety magazine as having gaping holes and jaw-dropping improbabilities, The Rock nonetheless almost went on to fool what should have been an altogether tougher critic: the British secret service.

One of the revelations in the Chilcot Report describes how a source described to Foreign Secretary Jack Straw as genuine with direct access in Iraq almost fooled MI6 into believing Saddam Hussein possessed similar weapons to those dreamt up by filmmaker Michael Bay.

In early October, questions were raised with SIS about the mention of glass containers in the 23 September 2002 report 47, the report said.

However, it was pointed out that glass containers were not typically used in chemical munitions; and that a popular movie (The Rock) had inaccurately depicted nerve agents being carried in glass beads or spheres.

The secret service questioned about the use of the glass containers like those in The Rock and found there were some precedents for the use of glass containers.

However...the sources description of the device and its spherical glass contents was remarkably similar to the fictional chemical weapon portrayed in the film The Rock, Chilcot concluded.

In the end suspicion grew and the evidence was discarded because the main source may not have written up the intelligence in the manner which was being claimed for him.