Only one in 25 British Muslims believe Al Qaeda was responsible for the September 11 attacks on the US, a poll has found.

The research said it was ‘deeply troubling’ that so many were willing to ‘entertain wild and outlandish conspiracy theories’.

A survey of more than 3,000 Muslims found 96 per cent did not believe Osama Bin Laden’s terror group carried out the atrocity. Some 31 per cent thought the American government was behind the strikes on the World Trade Centre and Pentagon, which claimed almost 3,000 lives. Another 7 per cent said it was a Jewish plot, while 58 per cent did not know.

A survey of more than 3,000 Muslims found 96 per cent did not believe Osama Bin Laden’s terror group carried out the atrocity

The poll, for the Policy Exchange think-tank, found 93 per cent of those quizzed had a strong attachment to the UK, and more than half wanted to fully integrate with non-Muslims in all aspects of life.

Muslims were also more engaged in the political process than the population at large, and significantly more likely to have raised money for charity or volunteered at a local school.

However, it was described as ‘a cause for concern’ that one in four British Muslims did not believe extremist views existed – despite a spate of major terror attacks and the rise of Islamic State.

The research said it was ‘deeply troubling’ that so many were willing to ‘entertain wild and outlandish conspiracy theories’

Almost half would not report it to the police if someone they knew was involved with supporters of terrorism in Syria.

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

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

Some 31 per cent thought the American government was behind the strikes on the World Trade Centre and Pentagon, which claimed almost 3,000 lives

British Muslims were more likely to condemn terror attacks than the population as a whole – 90 per cent compared to 83 per cent.

And attitudes towards many other issues, such as the NHS and immigration, were broadly in line with the rest of the nation. ICM, which carried out the survey for centre-Right think tank Policy Exchange, calls itself the ‘UK’s most respected pollster’. It questioned 3,040 British Muslims face-to-face between May and July last year and spoke to ten focus groups.

Birmingham Labour MP Khalid Mahmood, who is Muslim, said many of the findings showed the religious group were among the most ‘loyal, patriotic and law-abiding citizens’.

But in a foreword to the report, he wrote: ‘It is obviously a cause for concern that so many within our communities should doubt the very existence of [extremism], even as we face a severe and ongoing terrorist threat.

‘Even more startling is the fact that so many British Muslims seem ready to entertain wild and outlandish conspiracy theories ... believing that dark forces are at work to “do us down” as Muslims. It is deeply troubling that this seems to have led a not-insignificant minority to believe that the world is at the mercy of the machinations of dark, anti-Muslim forces.’ The research also revealed the Muslim Council of Britain, often billed as a spokesman for the community, reflected the views of only 4 per cent of those polled. But in a statement, the council said the Policy Exchange was trying to ‘delegitimise the organisation’.