Image copyright @GorillaSaver

A man crawling the London Marathon dressed as a gorilla is approaching the course's half-way point, three days after the race began.

Tom Harrison - who calls himself Mr Gorilla - is aiming to complete the 26.2 mile route on his hands and knees, "gorilla-style", in aid of The Gorilla Organization.

The charity's director said she was "so proud of him".

When not dressed as an ape, the north London father-of-two is a policeman.

Setting off at about 08:00 BST each morning, Mr Gorilla is expected to finish the marathon on Thursday or Friday.

Image copyright @GorillaSaver Image caption Mr Gorilla at mile ten

The 41-year-old, who sleeps at friends' houses after completing between 10 and 12 hours each day, is no stranger to fundraising challenges in his furry black costume.

He ran last year's marathon in the suit and in January this year, he swam in the Thames.

It is all in aid of the Gorilla Organization - a conservation charity with projects in Rwanda, Uganda and the Democratic Republic of Congo.

He said: "It's hard work today. All of my muscles are aching now so I've probably had a few more stops than previous days, but I'm still going forward so that's what matters.

"It's all about raising the profile of the Gorilla Organization and raising money. I don't really matter that much, I'm just a conduit to the gorillas in Africa."

Image copyright Twitter

Charity director, Jillian Miller, called him one of the charity's "top fundraisers".

She said: "He's one of those incredible people - when he sets his mind to something, he's going to do it."

Mr Gorilla has aimed to raise £2,000, which Ms Miller said would pay for at least three months' worth of supplies and salaries for a team of rangers protecting gorillas in Eastern Congo.