The 21-year-old man, whom police have refused to name, was returning from the war-torn country via Istanbul, the Metropolitan Police said in a statement on Thursday afternoon. Officers from Counter Terrorism Command (SO15) stopped him after disembarked a flight at around 2pm the same day and held him on suspicion of an offence contrary to Section 6 of the Terrorism Act 2006.
“He remains in custody at a West London police station. This arrest was not in response to any immediate threat or risk,” read a Scotland Yard statement.
This arrest follows that of former Guantanamo Bay detainee Moazzam Begg, who was detained by West Midlands Police and remanded in custody after being charged with terrorism offences related to the civil war in Syria.
A 36-year-old man from Shirley, in Solihull, and a 44-year-old woman and her 20-year-old son, both from Sparkhill, in Birmingham, were arrested along with Mr Begg on suspicion of facilitating terrorism overseas a little more than a week ago.
Passing through Turkey is a well-established route for people travelling to and from Syria.
Counter-terrorism investigators have expressed concern about aspiring British jihadis travelling from the UK to Syria to learn how to fire guns and make bombs.
It emerged last month that 250 UK-based extremists who went to train and fight in Syria have returned to Britain.
In January alone, 16 people were arrested on suspicion of terrorism offences related to Syria compared with 24 arrests in the whole of last year.
There were also reports that the first UK jihadi had staged a suicide attack in Syria.
Abdul Waheed Majeed, 41, was suspected of being responsible for driving a lorry to a jail in Aleppo and detonating a bomb. He is among an estimated 20 Britons who have been killed in the fighting in the war-torn state.