Suspected Islamist militants, one a close associate of hate preacher and jihadist recruiter Anjem Choudary, have been detained after attempting to leave Britain disguised as illegal immigrants.

The two terror suspects were found in the back of a truck in an attempt to leave Dover and cross into mainland Europe, hiding among a group of other people attempting to illegally exit the country.

Five men in total were arrested by counter-terrorism police and were believed to be heading to Europe with the aim of finally reaching Syria and join fellow jihadists.

The third man was detained attempting to depart Dover illegally later in the day while the other two in the five arrested were detained in London, suspected of assisting the men leave Britain.

According to The Telegraph, one of the men arrested at Dover was one of nine people, including Choudary, arrested in September in an investigation into Islamist terrorism in Britain.

All nine of those arrested were detained on suspicion of being supporters of the banned radical Islamic organisation, Al-Muhajiroun, before being released on bail.

Over 500 British nationals are believed to have reached Syria to fight for jihadist groups, including the Islamic State [IS].