It appears to show him calling for direct action against MPs who support Covid restrictions.
Piers Corbyn has been arrested on suspicion of encouraging people to attack MPs’ offices.
The Met Police said the arrest related to a video filmed during Saturday’s rally in London against Covid restrictions.
He was arrested in south London in the early hours of Sunday.
The force did not name Mr Corbyn however it previously said it was assessing a video which appears to show him calling for direct action.
The video, shared on social media on Saturday evening, appears to show the 74-year-old prominent anti vaccination campaigner criticising MPs who supported the introduction of Plan B measures.
After decrying “those scum who have decided to go ahead with introducing new fascism”, he tells a crowd to find out if their MP supported the new restrictions.
Plan B, which was approved in a vote in Parliament on Tuesday despite a Tory rebellion, includes the introduction of Covid passes – requiring proof of double jab or negative test – to access certain venues like nightclubs.