This week a number of newspapers, including The Telegraph, The Times, The Sun, the Daily Mail and the Daily Express, claimed that thermal imaging video footage showed that only one in ten Occupy London protesters at St. Paul's stayed in their tents overnight.

While the protesters themselves have conceded that some of their number do come and go in the evenings, the story behind this claim is a little more complicated.

Originally the figure was said to have been arrived at after a police helicopter used a thermal imaging camera to discover that "only around 20 of the 200 tents on the encampment actually have people staying in them." (Daily Telegraph)

This was later disputed by the City of London police who, according to The Guardian, said that whilst they can neither confirm or deny the accuracy of this claim, it did not come from them.

The Telegraph then went out and did some of their own research with an infra-red camera, which they claimed verified that 90 per cent of tents were unoccupied over night.

But how much store we can set by this footage has become the source of much controversy.

On Wednesday the Guardian sought the advice of an unnamed military scientist, who argued that "they cannot make the assumption that they have made from those images. The way they are set up, you wouldn't be able to tell if there's anyone in the tent or not."

To apparently demonstrate this point, the protesters today posted video footage online which they claim was shot with the same thermal camera as was used by the Telegraph. The results - shown below - appear to show that the thermal camera fails to detect when a tent is occupied.

 

While we cannot verify whether or  not the test is a fair one - we don't know, for example, whether the camera is the same one, how long the protesters have been in the tent when the video was shot, or whether the tent was a typical example of the ones being used by protesters - the footage has led some to call for the papers to correct their original stories.

If the protesters are confident that this video evidence is as strong as they claim, then we would certainly recommend pursuing complaints with the papers and the PCC. In our experience it takes time and persistence to get corrections and newspapers will try to fob off complainants along the way, but whether for the protestors or anyone else, Full Fact is always happy to advise how to get proper corrections to demonstrably inaccurate stories.