Officers have interviewed a man in his 50s at a police station in Hertfordshire and are searching for a second man who has been identified, the Met said in a statement on Tuesday.
Dramatic footage showed Watt being confronted by protesters close to Downing Street on Monday ahead of Prime Minister Boris Johnson’s announcement that the further lifting of Covid-19 lockdown in England would be delayed by four weeks.
Watt was filmed approaching members of a group called Resistance GB, before he was accosted and chased, and eventually escaped behind a police line.
“We also want to hear from anyone who can identify others involved in the incident,” the Met statement said.
“We acknowledge the concerns that have been raised about the police response during this incident,” it added, saying the force’s handling of “policing of events for all Londoners” would be reviewed.
Johnson earlier condemned the incident, saying in a tweet it was “disgraceful to see the hounding of Nick Watt doing his job.”