A technician has captured footage of a suspected shark swimming off the coastline.

Ronnie Hill was working at the London Array wind farm in the Thames Estuary when he spotted a fin cutting through the water.

The 38-year-old believes he has footage of a basking shark, a species found in British waters.

He captured the video on Sunday afternoon off the Thanet coast.

“I work offshore at the London Array wind farm and we had finished for the day,” the Aylesham resident said.

“We had brought all our tools downstairs ready to get on the boat.

“My colleague and I looked in the water where we thought we saw two porpoises as we see them quite a lot.

“But we looked again and thought it was one massive fish rather than two.”

He started filming the creature on his phone before doing some research online.

And it was soon revealed it was likely to be a basking shark.

“I have never seen one of those in the nine years I have worked here,” he added.

“We have seen lots of porpoises and seals, but never a shark.

“I am not an expert but it was a shark due to the two fins.”

Although basking sharks are found in British waters, they are more commonly spotted near southwest England, Wales and the west coast of Scotland, according to the Natural History Museum.

The species is Britain's largest fish but feeds on tiny prey, filtering around two million litres of water per hour through its gills.

They can grow up to 12 metres long, which is about the length of a double-decker bus.

It has a wide-opening jaw which is white inside, with several rows of very small teeth.

David Cameron officially opened what was the world's largest operational offshore wind farm, London Array, in 2013

The then Prime Minister toured the site by helicopter and declared it a “huge privilege” to be in Margate for the opening.

He congratulated everyone who had been involved in the scheme, which he branded "great for Kent and great for Britain".