Watch: This Giant False Widow Spider Is The Size Of A MOUSE

This terrifying video shows that Britain’s most venomous spider could be getting BIGGER.

The footage, filmed in Edinburgh, Scotland, shows a huge false widow spider scuttling around its web in a gas ether box.

And the creepy-crawly immediately spun its way to the nightmares of arachnophobes as it measured around 10cm long - about the same size as a mouse.

Gas engineer John Buchan captured the beast on film while out working - and the sight sent shivers down his spine.

Beast: The false widow spider was a lot bigger than its normal size (SWNS)

The dad-of-one revealed: “I opened up the external gas meter and didn’t notice the spider straight away.

"Then I spotted it. It was about the size of a mouse - even bigger.

"I see spiders all the time doing this job by I have never seen anything like that.

"Its body was enormous - it had a big ball on its back.

"Its legs were thicker than anything I’ve ever seen - they were hairy and horrible.

"From its bottom legs to the top it was probably about 10cm long. It was about the size of a can of drink.

"It was moving around a lot. I touched it with something and it started running. It was moving quickly around the metre box.

Spider man: Gas engineer John spotted the arachnid while out working (SWNS)

"I showed the tenant a photo of it and he said, ‘I hope it doesn’t get in here’.”

John showed four-year-old daughter Grace the video when he got home - and its fair to say she wasn’t happy.

He added: “She jumped out of her skin. She is so scared of them.

“If you don’t like spiders, the video is definitely not something you would want to watch.”

False widow spiders usually grow to the size of a 20p coin and have dark, shiny bodies with pale markings.

They pack a poisonous, painful bite which can trigger serious allergic reactions causing chest pain, swelling and nausea.