This week’s forensic exposure by the BBC programme Newsnight of the apparent fabrication of evidence underpinning an inflammatory report into British Muslims by the Tory-linked think tank Policy Exchange has revealed the soft underbelly of what has become an increasingly poisonous and dangerous campaign.

Throughout this year, a steady stream of hostile and sensationalised stories about the Muslim community in both press and television – often based on research by apparently reliable think tanks – has helped feed anti-Muslim prejudice to the point where Britons were found this summer by a Harris opinion poll to be more suspicious of Muslims than Americans or citizens of any other major west European country.

Policy Exchange’s October report, The Hijacking of British Islam: How extremist literature is subverting Britain’s mosques – which claimed that a quarter of a representative sample of 100 mosques had been found to be selling "extremist material, some of it anti-semitic, misogynistic, separatist and homophobic" – was a typical case. The story was given top billing by several newspapers and broadcasters, including the Times (on its front page) and the BBC.

On Wednesday, Newsnight – which had been going to run Policy Exchange’s report as an exclusive story – revealed that it had investigated five out of 25 receipts for such literature provided by Policy Exchange’s researchers and found clear evidence that they had been faked, written by the same person and/or were not issued by the mosques in question. Policy Exchange insists it stands by its research, but so far refuses to say whether it believes the receipts are genuine.

It might be assumed from this that the other 20 receipts were found to be authentic and that Policy Exchange’s basic case was solid. It has now become clear that is not the case. Newsnight insiders make clear that they didn’t have the time or resources to check the other receipts – and in at least one of those that they didn’t look into, supposedly issued by Edinburgh central mosque, the mosque authorities have said that leaflets claimed to have been found there calling for the killing of the apostates were in fact dumped in the mosque grounds after the report was published.

Given the clear evidence of falsification at the heart of Policy Exchange’s work, it cannot be taken in any way as a piece of reliable research – and there must be serious doubt as to whether the 100 mosques supposedly surveyed were in fact a representative sample. Policy Exchange has form in this area: earlier this year, the methodology and reliability of another heavily-publicised Policy Exchange report on alleged British Muslim attitudes, Living Apart Together, came under heavyweight academic attack.

Of course, as Soumaya Ghannoushi remarks today in a blog for the 1990 Trust: "Islamic bookshops are a far cry from Waterstones or Borders. Some of the books on sale on djinns, angels, dreams, signs of the day of judgement and hellfire often make me laugh/cringe/both". You can also see plenty of ugly material in other religious institutions in Britain, such as the homophobic pamphlets I recently found on display in a south London evangelical church.

But the constant regurgitation by the media of Muslim-baiting "research" by hard right think tanks (the Centre of Social Cohesion is another offender) not only misleads the public about one of the most sensitive issues of our time – it is also clearly driven by a neoconservative political agenda, which seeks to convince people that jihadist terror attacks in Britain and elsewhere are driven not by outrage at western violence in the Muslim world but by opposition to western freedom.

A quick glance at the profiles of those involved in Policy Exchange underlines the point. Its policy director, Dean Godson, who blustered at Jeremy Paxman on Wednesday, worked for the Reagan administration in the US as special assistant to the secretary of the Navy, John Lehman, was a signatory to the The Project for a New American Century and was special assistant to the jailed former Telegraph owner Conrad Black. Charles Moore, the former Daily Telegraph and Spectator editor who has made the case for public debate about whether the prophet Muhammad was a paedophile, is the Policy Exchange chairman. And who did he replace? Policy Exchange’s co-founder, Michael Gove – author of that rallying text for British neocons Celsius 7/7 – and now David Cameron’s education spokesman.