A 57-year-old man has been arrested for allegedly possessing tear gas believed to have caused a partial evacuation at Heathrow Airport.

A terminal at Heathrow Airport has been evacuated as emergency services respond to a 'possible hazardous materials incident'.

A 'possible hazardous materials incident' saw Terminal 4 shut for around three hours shortly after 5pm on Monday, forcing crowds of people to gather outside while emergency crews…