A Metropolitan police officer who has been crawling the London Marathon in a gorilla costume since the race began on Sunday morning has completed the 26-mile route.

Don’t insult gorillas by comparing them to Donald Trump | Ros Coward Read more

Tom Harrison, who goes by the name Mr Gorilla, is raising money for the Gorilla Organisation. The 41-year-old Londoner started at 10.34am on Sunday and crossed the finish line at 11.45am on Saturday.

He has slept at friends’ houses in the evenings after completing about 10 to 12 hours and 4.5 miles per day and has swapped between crawling on hands and knees and up on hands and feet to save his blistered knees.

Harrison crossed the finish line on the Mall flanked by his two sons and beating his chest. He said: “It was tough at points, but I am really glad I did it.”

The Putney-based police officer said he had run the marathon in the gorilla suit last year, but this time wanted to do “that little bit more”. He said: “The first couple of days, people were giving me weird looks and a wide berth. But by day three more people had started hearing about it: I started getting people beeping their horns and clapping and cheering.”

On his unique view of the capital over the past seven days, he said: “One thing I noticed was that being at exhaust height, it was really catching my throat. You just notice the pollution side of things that much more.

Facebook Twitter Pinterest Tom Harrison: ‘The first couple of days, people were giving me weird looks and a wide berth.’ Photograph: John Stillwell/PA

“The other thing was just how limited my view was. I had helpers in front of me telling me to go left, right and so on so that I didn’t hit lamp-posts or trees.”

Harrison said he was most looking forward to getting a massage for his aching shoulders, and having a cup of coffee, as it had upset his stomach during the race. “Your stomach is not used to being in that position, so it gave me a bit of heartburn,” he said.

He was met at the finish line by Gorilla Organisation chair Ian Redmond and conservationist Bill Oddie, who handed him a trophy and a stuffed gorilla.

The Gorilla Organisation is dedicated to conserving gorillas in Rwanda, Uganda and the Democratic Republic of the Congo. Harrison’s JustGiving page for his marathon effort has so far raised more than £23,000 for the charity.

In his costume, the police officer has taken part in a series of fundraisers for the cause, including the Great Gorilla Run, Tough Mudder and running the same marathon last year.

“He’s just this incredible personality who seems to me to be absolutely fearless, but he loves the gorillas.” said Jillian Miller, the charity’s director. “I thought he was mad at first, but you know when Tom sets his heart to do something, he absolutely does it.”