Police arrested British far-right activist Tommy Robinson on Monday on suspicion of committing assault last week at a London train station.

British Transport Police said in a statement they arrested a 42-year-old man at Luton airport, north of London, "in connection to an assault at St Pancras station on 28 July".

"The man had been wanted for questioning after leaving the country to Tenerife in the early hours of 29 August following the incident at St Pancras," it said.

Although the statement did not directly name Robinson, he was seen in a video widely shared on social media last week of an incident at Saint Pancras.

Robinson, whose real name is Stephen Yaxley-Lennon, is seen walking next to a motionless man laying on the floor, alleging that the man had "come at me".

He was arrested on Monday after returning to Britain on a flight from Portugal "on suspicion of... grievous bodily harm and will now be taken to custody for questioning".

Robinson has become a champion for far-right and anti-immigrant factions.

The former football hooligan, who founded the far-right English Defence League in 2009, has repeatedly been convicted for public order and contempt offences.

He has also been blamed for helping fuel racially aggravated riots that rocked the country in 2024, which he denies. (AFP)