A new report claims Saudi Arabia is biggest foreign promoter of Islamist extremism in the UK.
The Henry Jackson Society reported that most funding for extremism comes from governments which are situated in Iran and the Gulf States.
The think tank claims that during the past 30 years, Saudi Arabia spent more than $70 billion (£54 billion) on exporting Wahhabi Islam - a strict version of Islamic based on a literal interpretation of the Quran - to the rest of the Islamic world.
The report finds: "The foreign funding for Islamist extremism in Britain primarily comes from governments and government-linked foundations based in the Gulf, as well as Iran. Foremost among these has been Saudi Arabia, which since the 1960s has sponsored a multimillion dollar effort to export Wahhabi Islam across the Islamic world, including to Muslim communities in the West.
"In the UK this funding has primarily taken the form of endowments to mosques and Islamic educational institutions, which have in turn played host to extremist preachers and the distribution of extremist literature.
"Influence has also been exerted through the training of British Muslim religious leaders in Saudi Arabia, as well as the use of Saudi textbooks in a number of the UK’s independent Islamic schools."
The World Assembly of Muslim Youth and the Muslim World League are specifically mentioned by the report, both have been funded by Saudi Arabia.
The report claims the youth group has a wide history of promoting Islamist extremism as well as providing hate literature.
Howevewr the Saudi embassy has said the claims are "categorically false."