Former English Defence League leader Tommy Robinson has been arrested on suspicion of assaulting a man he claims spat in his face.
Mr Robinson, 37, was detained at a protest rally at Hollywood Retail Park in Barrow, Cumbria, shortly after 20:30 BST on Thursday.
Three other men from outside the Barrow area were also arrested on suspicion of a public order offence.
The rally was about an investigation into allegations of sexual “grooming”.
Cumbria Police said a one-year investigation had failed to find evidence of a grooming gang.
Mr Robinson, whose real name is Stephen Yaxley-Lennon, is also being questioned on suspicion of a public order offence, along with a 43-year-old man from the West Midlands area, a 47-year-old man from the North Wales area and a 28-year-old man from the Bedfordshire area, all of whom are still in police custody.
In a video filmed by Mr Robinson and shared online, he said he was speaking to people at the shopping park when a man spat in his face.
The video shows Mr Robinson telling police he “acted in self-defence”.