Protesters and politicians are concerned about Mr Wilders' film

National Counterterrorism Co-ordinator Tjibbe Joustra is said to have warned the politician amid growing concern.

The Dutch prime minister has spoken of fears the film could be offensive and "lead to reactions that endanger public order, security and the economy".

One Iranian politician has warned of repercussions from the Muslim world.

Alaeddin Boroujerdi, head of the Majlis National Security and Foreign Policy Commission, has called on the Dutch government to prevent Mr Wilders showing his film.

"Otherwise, the Majlis deputies will call on the Iranian government to review its relations with the Netherlands," he told the Iranian news agency IRNA.

Koran criticised

Mr Wilders, the head of the Freedom Party and a lawmaker, has had police protection since Dutch director Theo Van Gogh was killed by a radical Islamist in 2004.

Mr van Gogh's film Submission included texts from the Koran shown against a naked female body.

Van Gogh was killed by a radical Islamist over his film Submission

In the past, Mr Wilders has said the Koran is incompatible with Dutch values.

The National Counterterrorism Co-ordinator's office said it was in regular contact with Mr Wilders, but would not disclose details of talks.

Mr Wilders has said his film will show how the Koran is "an inspiration for intolerance, murder and terror".

The exact content of the 10-minute film is not yet known, but Mr Wilders says he will screen it on the internet if he cannot find a willing broadcaster.

Prime Minister Jan Peter Balkenende said there were "major concerns at home and abroad that the film could be offensive and could lead to reactions that endanger public order, security and the economy".

"The Netherlands has a tradition of freedom of speech, religion and lifestyle," he said.

"The Netherlands also has a tradition of respect, tolerance and responsibility. Unnecessarily offending certain groups does not belong here."

As well as the killing of Mr van Gogh, politicians are mindful of the widespread protests by Muslims that followed the publication of cartoons satirising the Prophet Muhammad in newspapers in Denmark and other European countries in 2006.