Video posted online showed the far-right activist near a man lying on the ground at St Pancras station
The far-right activist Tommy Robinson has been arrested over an alleged assault in London.
In a statement British Transport Police said: “Officers from BTP have tonight (4 August) arrested a 42-year-old man from Bedfordshire in connection to an assault at St Pancras station on 28 July.
“The arrest took place at Luton Airport shortly after 6.30pm, following a notification that the man had boarded an incoming flight from Faro.
“The man had been wanted for questioning after leaving the country to Tenerife in the early hours of 29 July following the incident at St Pancras.
