The two 'bag experts' tried 400 times between them, but neither could fit themselves inside the North Face holdall and then padlock it from outside. "Even Houdini would have struggled" concluded one in resignation.
The inquest into the death of Gareth Williams, a MI6 officer whose body was found naked in a bag at his home, saw video footage of attempts to get inside a similar holdall, measuring 32ins by 19ins, and then lock it from the inside.
Afterwards, giving evidence, Peter Faulding stated that a 'third party' must have been responsible.
"I just cannot do it. This case, I just cannot get it off my mind. It is very difficult. I am an escapologist, I am thinking outside the box here and trying everything I can to find a way. I cannot say it was impossible, but even Houdini would struggled" said Mr Faulding who has had 300 attempts at the task.
But William MacKay, who has had a hundred goes without success, maintained that it was actually possible that the MI6 officer could have locked himself in. "I would not like to say that it could not be done. There are people around who can do amazing things and Mr Williams may well have been one of those persons" he stated.
Mr Williams' mountain climbing experience would have given him an advantage as it would have strengthened his fingers, held Mr MacKay, who said that working with the military had given him the ability to operate in confined spaces.
He had used an yoga practising assistant who was of similar build to the 31 year old computer specialist: "He is very flexible and if the task could be done and he is the person that could do it".
But the assistant could not, in fact, do it and neither could Mr MacKay "It was very painful to do it. You tend to move the zip with your finger nails, straggling about. It was very frustrating, fiddly, you just can't get the thing together."
In any event, their experiment had not involved a bath, the inquest was told.
Mr MacKay considered whether the bag could be opened using a 'baggage handler's technique' in which a pen is used to lever the closed zip apart. But in tests the zip did not close neatly, and became obviously damaged.
Westminster coroners' court has heard earlier that Mr Williams, who was on secondment to the Secret Intelligence Service [MI6] from the GCHQ had trawled bondage and sadomaschism websites and his flat was found to contain £ 20,000 worth of female designer clothing and wigs.
Whether he had locked himself into the bag, or been placed there, the inquest was told, Mr Williams could not have survived for more than 30 minutes as the temperature quickly rose and oxygen levels dropped. Mr Faulding who runs a company called International Mine Rescue, said he only lasted five minutes before becoming 'delirious' after zipping himself inside with emergency oxygen and a paramedic outside.
He had to use a bathroom wall to lower himself into the bag, whereas the inquest had heard that no finger or palm print of Mr Williams had been found in the relevant area. Furthermore it proved to be extremely difficult, he added, to place the padlock key where it was found, underneath the right buttock of the corpse.
However, he said it would have been 'easy' for one person to lift the sturdy bag carrying the body of Mr Williams, who weighed 60 kilos, into the bath, said Mr Faulding: "My conclusion is that Mr Williams was either placed in the bag unconscious, or he was dead before he was in the bag".