An Islamic preacher from Egypt told a conference in Melbourne Muslims have a compulsory duty to spread Islam in any nation where they are the minority to prevent sin.

Sheikh Ibrahim Zidan told a hardline Sunni forum it was compulsory for Muslims to engage in dawa, the term for politically promoting Islam.

'When Muslims are minorities, the dawa is either a mandatory thing for everyone or whoever does the work of dawa and it's efficient, then it's not mandatory for the rest,' he told the Ahlus Sunnah Wal Jamaah Association's annual conference.

'If it's not done in the most sufficient way, that means that everybody becomes sinful.'

Islam critic Ayaan Hirsi says Muslims are spreading Islam by exploiting political correctness

Somali-born Islam critic Ayaan Hirsi Ali said Muslims in Australia had been able to spread Islam by exploiting 'prevailing politically-correct' attitudes.

'But they're very radical in their thinking. They promote Sharia law,' she told Daily Mail Australia from an undisclosed location in the United States.

'They promote the segregation of men and women.

'They're homophobic. They promote the idea that to leave Islam is to earn the death penalty and in general they promote this idea that Islam is superior to everything and so their followers are made to accept the idea to be hostile to the infidels, to Australian society, to all non-Muslim society.'

Sheikh Ibrahim Zidan told a Sunni group's annual conference it was mandatory to spread Islam

Islam critic Ayaan Hirsi Ali said Muslims were encouraged to isolate themselves from society

Daily Mail Australia has witnessed the segregation of men and women at an ASWJ mosque at Auburn in Sydney's west.

It is upstairs from the Bukhari House Islamic Bookstore which sells books promoting Sharia law and explaining how the death penalty is applied for homosexuality and leaving Islam.

The bookshop is a separate entity to the ASWJ but it shares the same street entrance on Auburn Road.

However, the Sunni group in Sydney's west has hardline preachers who have described as sinful the idea of attending non-Muslim events like the Easter Show and having non-Muslim friends.

The Bukhari House Islamic Bookstore in Sydney sells titles on Muslim Sharia law punishments

Ayaan Hirsi Ali says Muslim activists want to convert more people to Islam

Ms Hirsi Ali said many mosques had manuals explaining how to spread Islam, and ultimately Sharia law, through political and legal means.

'The first thing they want to do is isolate Muslim communities from the rest of society, use the isolated community as a vanguard,' she said.

'They want to convert non-Muslims to Islam and they want to Islamise institutions and some of these demands have been successful that they are governed by a different set of rules.

'The Muslim communities, through immigration and their birth rates, they want to make way more effort to convert more people.'

Official Australian Bureau of Statistics figures from the 2016 Census revealed the Muslim population in Australia soared to more than 604,000 people, overtaking Buddhism as the most popular non-Christian religion.

The number of Muslims living in the country has almost doubled from 341,000 in the the 2006 census, making them 2.6 per cent of the Australian population.