A mysterious "big cat" has been spotted close to the Warner Brothers film studios in Leavesden by a stunned motorist.

Calvin Jayasinghe, 62, spotted the beast in Aerodrome Way, Leavesden, as he was driving to pick up his wife from work in Hemel Hempstead at around 9.30pm on Wednesday last week.

The road runs adjacent to The Making of Harry Potter tour and Leavesden film studios although there is no suggestion the sighting is connected to activities at either.

Solicitor Mr Jayasinghe, of The Ridgeway, Watford, described how something bigger than a cat leapt out in front of him as he drove along the road. It then prowlied off in the direction of Abbots Langley.

He said: "It was just before the traffic lights, I saw something big and black with a long tail.

"It was not a dog or fox, it didn’t look like either of them. It was a cat.

"It was hard to see it clearly because it was dark but it looked big and black, it looked at me then it just walked off."

Mr Jayasinghe said the whole incident was over in a few seconds and was given no time to photograph the animal.

This is not the first reported big cat sighting in south west Hertfordshire in recent years.

Last August, a similar sighting was made near the rear of Watford General Hospital .

Large black cats have also been spotted near Sarratt, Kings Langley and Bricket Wood. The much-discussed "Beast of Bedmond" has even been accused of killing sheep and birds.

Big cat expert Danny Nineham, who stressed that the Bedmond incidents were most likely the work of a large dog, has stressed that wild "big cats" are by no means uncommon in the UK.

Many big cats, he said, were released into the wild in the 1970s when the keeping of "exotic pets" was outlawed on safety grounds and have been breeding ever since.

Speaking in 2009 he told the Watford Observer: "These cats are potentially dangerous. Anyone who says they are not should visit a zoo and look through the fence at a leopard or lion and ask whether they’d like to go inside.

"It’s almost unheard of that they would attack a person because they have such a lot of food available to them in this country.

"The problem comes when you disturb them in their natural habitat and they see you as a threat - then they can be dangerous and unpredictable."