A police officer who moved English Defence League (EDL) founder Tommy Robinson on from a pub has told a court he did not know who he was.
The 36-year-old, in court under his real name Stephen Yaxley-Lennon, was at a Cambridge pub after a football match in August 2016.
Mr Yaxley-Lennon claims he was "targeted because of his beliefs".
His harassment claim against Cambridgeshire Police is being heard at Peterborough County Court.
Sgt Paul Street told the court he thought the name Tommy Robinson referred to an "'80s football hooligan".
He said: "I didn't know what he looked like, but I had heard the name."
Mr Yaxley-Lennon said he had been with his three children, aged between five and nine, to watch Luton Town play Cambridge United in August 2016.
A dispersal order was used by officers, and Mr Yaxley-Lennon claims he was followed part-way to the train station.
Sgt Street told the court he believed the activist had been with a group of Luton fans who might cause trouble.
He said: "This is nothing to do with Tommy Robinson. It's about keeping 'risk' supporters out of an environment where they're likely to cause trouble."
Alison Gurden, acting for Mr Yaxley-Lennon, put it to Sgt Street that her client had not been drunk at the time.
Sgt Street said: "I would find it very hard to accept that because he smelt of alcoholic drink. He was becoming irate and he smelt of alcoholic drink."
The case continues.