It follows an interview with Fox News in which he also claimed that there are "Muslim religious police" in London who "beat anyone who doesn't dress according to Muslim, religious Muslim attire".
His comments triggered thousands of tweets using the hashtag #foxnewsfacts.
PM David Cameron said the interview made him choke on his porridge.
But Mr Emerson is not the first to get his facts wrong. Here are some other common #fails when it comes to understanding Islam.
Back in October, political comedian Bill Maher made some pretty controversial remarks surrounding Islam on his HBO show, Real Time with Bill Maher.
The city's population estimated at 1,073,045
Christian: 494,358
Muslim: 234,411
Sikh: 32,376
Hindu: 22,362
Buddhist: 4,780
Jewish: 2,205
Other: 5,646
No religion: 206,821
Religion not stated: 70,086
Source: Census 2011
Maher has been critical of organised religion throughout his career, concentrating particularly on Islam.
But this recent debate on the topic got pretty heated when actor Ben Affleck appeared on the panel and called the host's view "gross and racist".
One of the main things people complained about was that Bill Maher was pretty quick to suggest all Muslims have the same belief system.
Although there are several basic beliefs in Islam, there are different groups of Muslims such as the Sunnis and Shi'ites.
The differences within Islam started when the Prophet Muhammad died and there were disagreements about who should lead the Muslim community.
Sunnis and Shi'tes have different versions of the Hadith (the book of Muhammad's sayings) - which means they have a slightly different understanding of Islam.
Overall, Islam is a diverse religion and there are different interpretations of the Qur'an.
A basic issue in this statement is that people often don't fully understand what the garment is.
A burka, sometimes spelled burqa, is the all-enveloping cloak, often blue, with a woven grill over the eyes, that many Afghan women wear.
On the day that France became the first European country to ban the full-face Islamic veil in public places, the Today programme reported: "About 2,000 are said to wear the full veil and even that is a generous estimate according to some charities."
Other veils which cover the body and face are called niqabs and hijabs - the latter is often simply called a headscarf because a woman's full face is visible.
See the difference between all the veils
No. Only if you live in Saudi Arabia where the law is being reviewed.
In November, a member of the king's advisory council said the country was considering proposals to allow women to drive.
The recommendations from the Shura Council to change the law would apply only to women over 30 - and they would only get to drive before 8pm.
Nevertheless, such a move would represent a major victory for activists after years of rejection of any review of the ban.
Earlier this year, a woman reportedly received 150 lashes for being caught driving.
But Saudi Arabia is the only country in the world that forbids women from getting behind the wheel.
The literal meaning of Jihad is struggle or effort, and means more than holy war.
Muslims use the word to describe three different kinds of struggle:
- A believer's internal struggle to live out the Muslim faith as well as possible
- The struggle to build a good Muslim society
- Holy war: the struggle to defend Islam, with force if necessary
In the days since the Paris attacks, Muslim leaders around the world have condemned any use of violence in the name of Islam.
Only if you agree with ex-UKIP leader Lord Pearson.
In 2013, he warned UK Muslim communities were home to "thousands of potential home-grown terrorists".
Such people "hate us with frightening religious fervour," he said, during a parliamentary debate on Islam, in which he criticised Sharia law.
So what is Sharia?
Sharia law, or Islamic religious law, is practised by many strict Muslims.
Some interpretations involve harsh physical punishments for theft and adultery.
Making money from money is not allowed. That means interest on money in bank accounts is off limits, but making a profit through trading is permitted.
There have been reports of growing use of Sharia law by UK Muslims, with several Sharia courts in operation.
But among western nations only Canada is reported to have come close to allowing full Sharia law, but it didn't happen in the end following protests back in 2005.
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US terrorism "expert" Steven Emerson has apologised for describing Birmingham as a "Muslim-only city".