"On Saturday, 7 April, Detectives from the Met's Counter Terrorism Command arrested a 55-year-old man on suspicion of encouragement of terrorism and dissemination of terrorist publications, contrary to the Terrorism Act 2006," Met Police said in a statement.
The man was arrested at 11.02 GMT at Gatwick Airport when he arrived at the United Kingdom from Morocco, it noted.
The suspect is held in custody at a south London police station, the statement continued.
READ MORE: UK Police Arrest Woman at Heathrow Airport on Suspicion of Terror Activity
The United Kingdom has faced a number of terror attacks in 2017, most prominently three attacks in London, which took place in Westminster, on London Bridge, and outside the Parsons Green Tube station, and a bombardment at a concert in Manchester on May 22, the latter of which took the lives of over 20 people and left several hundreds wounded.