And it led to the launch on Thursday of the book Islam FAQ.

Reverend Fred Nile officially launched the book, describing it as “a very valuable publication”.

Reverend Nile said Islam was “a major world religion” that was strong in areas close to Australia, including Indonesia.

“They’re right on our doorstep, so we need to know about them, and we need to know facts,” Rev Nile said.

He said the book was not propaganda and by sticking to the facts it “fills a gap in the publications available on the subject”.

Mr McCrudden revealed the book was borne out of the September 11 attack, and it was no coincidence the book was launched on the seventh anniversary of the terrorist attack on the World Trade Centre.

Following the attack when the whole world was talking about Muslim terrorists, Mr McCrudden realised he knew nothing about Islam except it mentioned something called Mecca.

“I wrote it because I was profoundly ignorant of something I should have known something about,” he said.

And Mr McCrudden started researching Islam “to satisfy my own curiosity”.

The result was a book of questions and answers based on Islam’s holy book, the Koran, as well as the words of acknowledged leaders of the religion.

But there was a strong divergence of opinions on a whole range of issues, Mr McCrudden said, between different branches of Islam and the teachings of different leaders.

But one thing common throughout the religion was the aim of changing Western society to have all people adopt Islamic customs and laws, he claimed.

“It’s well worthwhile knowing that Islamists have a particular wish to have their customs made everyone’s customs,” Mr McCrudden said.

Those changes were already happening.

At Melbourne’s Monash University there were separate toilets for Muslims, Mr McCrudden said, and in England a small council that met around a table had abandoned having water and biscuits during meetings held during the holy month of Ramadan, at the request of two Islamic councillors.

Despite the concerns he raised, Mr McCrudden said he had no personal view on Islam as, “I’ve tried to keep this as objective as I can”.