Police are looking into a video appearing to show anti-migrant activist Daniel Thomas slashing at an inflatable boat with a knife in the English Channel.

The boat had been carrying about 50 migrants who had launched from a beach in Normandy. They were picked up by two RNLI lifeboats once they had reached the UK search and rescue area and were taken to Dover for processing.

Daniel Thomas, known to his supporters as Danny Tommo, had been filming the transfer from a yellow speedboat while giving commentary to a live stream audience of more than 15,000 people.

The video then shows him sailing up to the boat, taking out a small knife and start slashing at the side of the migrant boat.

There were no migrants on board, but there was a French official from the coastguard vessel Abeille Liberté.

As the Frenchman boarded the empty migrant boat mid-Channel Danny Tommo shouted “Right, you are on English territory. This is England. This is not France any more.”

Then he made a series of stabbing and slashing movements against the rubber side of the large inflatable boat.

“Get off – get off,” he shouted. “You’ve got time to get off the boat.”

It was not clear from the live stream if he did any damage to the boat.

“We just wanted to make sure that boat was not taken back to France and used again,” Tommo told his followers.

Posting on X, campaign group Stand Up To Racism described the footage as “disgusting”.

There is no evidence that any boats that have been used by migrants to cross the English Channel have ever been taken back to France for reuse.

Hampshire and Isle of Wight Constabulary said: “We are aware of a video circulating online relating to damage being caused to a boat in the English Channel on the afternoon of 22 September, and we are conducting inquiries into the matter.”