Tom Harrison, 41, who was fundraising for The Gorilla Organisation, completed the 26.2-mile course on April 29, six-and-a-half days after race day.

The policeman, also known as Mr Gorilla, covered almost five miles per day on his hands and feet, switching his technique from hands and knees to avoid blisters.

His efforts were richly rewarded as he reached 27x his fundraising target of £1,750.

Mr Harrison received £39,550 in donations by Saturday - one week after crossing the finish line - which with added gift aid of £7,500, brought his fundraising to £47,000 so far.

The keen fundraiser, who has previously competed in Tough Mudder and The Great Gorilla Run, slept in friends' homes after each gruelling 10 to 12-hour day.

The father-of-two from Buckinghamshire missed out on the marathon finishers' medal, awarded to runners who complete the race within eight hours, but was greeted with a trophy and a stuffed gorilla toy at the finish line.

The Gorilla Organisation protects endangered apes from extinction in Rwanda, Uganda and DR Congo.

Jillian Miller, director of the charity, said at the time: "He's just this incredible personality who seems to me to be absolutely fearless, but he loves the gorillas.

"I thought he was mad at first, but you know when Tom sets his heart to do something, he absolutely does it."