Extremist texts that encourage hatred of gays, Christians and Jews is available at Britain’s mosques.

Researchers for the centre-Right think tank Policy Exchange claim to have found such publications in a quarter of the 100 mosques and Islamic institutions they visited, including London Central Mosque in Regent’s Park, which is funded by Saudi Arabia.

Many of the publications allegedly called on British Muslims to segregate themselves from non-Muslims and contained repeated calls for gays to executed and for women to be subjugated.

Most of the material is produced by agencies closely linked to the Saudi regime, according to the investigation.

Dr Yunes Teinaz, of the London Central Mosque, told the Telegraph: “Any book or literature like this found in the mosque will reflect the views of the author and not at all the view of the mosque.”

Prime Minister Gordon Brown has been urged to challenge King Abdullah of Saudi Arabia about the literature when he meets him tomorrow as part of the King’s state visit to Britain.

Later today, the Queen will officially welcome King Abdullah in a lavish ceremony at Buckingham Palace.

The report is the most comprehensive academic survey of its kind ever produced in the UK and is based on a year-long investigation by several teams of specialist researchers.

Many of the institutions mentioned are among the best-funded and most active of Britain’s approximately 1,500 Islamic establishments.

Some have received official visits from politicians and members of the Royal Family.

Anthony Browne, the director of Policy Exchange, said in a statement: “It is clearly intolerable that hate literature is peddled at some British mosques.

“I am sure the majority of moderate Muslims will be as horrified as everyone else that pamphlets advocating jihad by force, hatred for insufficiently observant Muslims, Christians and Jews, and segregation have found their way into the UK’s mosques.”

Mr Browne added: “The fact that the Saudi regime is

producing extremist propaganda and targeting it at British Muslims must also be challenged by our own government.

“It is reassuring that the majority of mosques investigated do not propagate hate literature – but much work needs to be done to ensure that a large number of leading Islamic institutions remove this sectarianism from their midst.”

Policy Exchange said it found the literature was accessible both openly and “under the counter”.

They collected 80 books and pamphlets over the course of the year.

Iqbal Sacranie, a former secretary general of the Muslim Council of

Great Britain, has criticised the report.

He said: “The majority of Muslims will totally dismiss this because it is written by the Policy Exchange, who have an agenda to denigrate the mainstream of Islam in this country.

“If there is any material which falls foul of the law, then the law

should take its course. We cannot accept messages of hate – there is zero tolerance on that.

“But it is irresponsible to target religious texts and take them out of context. These texts can be found not just in mosques but in ordinary bookshops – the report overlooks that.”

The report is entitled The Hijacking of British Islam: How extremist literature is subverting Britain’s mosques.

It was written by Dr Denis MacEoin, the Royal Literary Fund Fellow at Newcastle University.

The report goes on to make several recommendations, including that mosques and other Islamic institutions must act immediately to remove extremist literature from their premises and that the government, local authorities, police forces, other institutions and prominent individuals should have nothing to do with

mosques that continue to sell or distribute extremist literature.