ALMOST half of British Muslims wouldn't go to the police if someone they knew was involved with supporters of terrorism in Syria.

A staggering new survey also found that just 26 per cent of Britain’s Muslims do not believe in “extremist views exist”.

6 Half of British Muslims wouldn't go to the police if they suspected someone of having IS links Credit: Alamy

The survey – dubbed the biggest ever of its kind – has revealed that only one in 25 British Muslims believe Osama Bin Laden and Al-Qaeda were responsible for the 9-11 attacks.

A Policy Exchange poll last night claimed 31 per cent believe the US Government was behind the atrocity than the terrorists – 4 per cent.

And seven per cent said the attack, which killed almost 3,000 people, was a plot by the Jewish community.

6 A new poll says almost a third of British Muslims thought the US Government was behind 9/11 Credit: AP:Associated Press

Two in five would support the introduction of sharia law, the legal system derived from the Koran.

The poll also found that 40 per cent were in favour of gender-segregated classrooms, while a further 44 per cent thought schools should force girls to wear traditional Islamic dress.

But the survey claimed that in nearly every walk of life the British Muslim community was no different in their views and priorities to their non-Muslim neighbours.

6 93 per cent of households had a strong attachment to Britain Credit: Alamy

The vast majority condemned terrorism, backed more police on the beat and listed the NHS, economy and immigration at the top of their concerns about the country.

Policy Exchange added that 93 per cent of the thousands polled had a “fairly” or “very” strong attachment to Britain.

Khalid Mahmood, Labour MP and co-author of the report, said it proved that British Muslims were “loyal and patriotic”. But he said it was clear there was still a sense of “victimhood” that allowed conspiracy theories to flourish.

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And he said it was “deeply troubling” that so many denied extremism appeared to be an issue.

He said: “It is obviously a cause of concern that so many should doubt the very existence of this phenomenon, even as we face an ongoing terrorist threat.”

The report, Unsettled Belonging: Britain’s Muslim Communities, is based on research carried out by polling company ICM with more than 3,000 people.

It found that more Muslims condemned terrorism than the rest of the population - 90 per cent to 84 per cent- and 55 per cent wanted to see extra police on the streets.

6 Most thought extremism was not a problem Credit: Alamy

One per cent said they favoured fully separate Islamic areas in Britain.

Martyn Frampton, head of security and counter extremism at Policy Exchange, said: “In nearly every walk of life, British Muslims are no different in their views and priorities to their non-Muslim neighbours.

“They believe the NHS, jobs and immigration to be the most pressing issues facing the country and worry deeply about the effect of drugs and drinking on their communities.

6 Just 4 per cent believed Osama Bin Laden and Al-Qaeda were responsible for 9/11 Credit: AP:Associated Press

“However, the research found a deeply worrying belief in conspiracy theories such as 9/11.

“Unlike the general population, nearly a third of British Muslims believe the American government was responsible for the attacks on the Twin Towers, while a surprisingly tiny number attributed blame to al Qaeda.”

The report found that the Muslim Council of Britain enjoys little support in the community, with just nine per cent of respondents backing it.

6 The research found a deeply worrying belief in conspiracy theories such as 9/11. Credit: Getty Images

It also suggested the Government should not be “spooked” into abandoning or apologising for its controversial Prevent agenda, which tries to stop people being drawn into terrorism, because Muslim communities are “generally relaxed” about intervention to tackle extremism.

David Goodhart, head of Policy Exchange’s demography, integration and immigration unit, said: “British Muslims as a whole continue to live somewhat more separately than other large ethno-cultural minorities - in neighbourhoods and schools, in terms of women not working and in terms of attitudes and religiosity.