Graham Burns trained on the beach - away from the crowds' ears

Graham Burns from Broadstairs carried a karaoke machine around the course and entertained the crowds with songs about running.

He belted out songs like Keep On Running, Run To You and Ain't Nothing Gonna Break My Stride as he pounded round London's streets.

Mr Burns says he is "a half decent runner but a terrible singer".

Thirty-song repertoire

He hoped to complete the course in about four hours and 30 minutes, but took five hours.

But he expects to raise more than �2,000 for the Breast Cancer Campaign charity.

He had a repertoire of 30 marathon-themed tracks, which lasted him about two hours - meaning he had to repeat each song at least once.

Before the race he said: "I enjoy running and my other hobby is music, so I thought let's combine them.

Friends and family obviously think I've lost it, but it's just a bit of fun Graham Burns

"I'm a half decent runner but a terrible singer but I thought 'let's go for it'.

"If I do it without singing, I can do it in about three-and-a-half hours, but I think it's going to be about four-and-a-half hours, maybe even a bit more."

Mr Burns trained around the Broadstairs area with his karaoke equipment strapped to him, to make sure he could manage running and singing at once - but he tried to keep as anonymous as a karaoke marathon runner could until the big day.

"I've tended not to go out in daylight with it on.

"I've done my running either on the cliffs where there's not many people about, or when it's dark.

"The biggest weight is the speakers strapped round my waist and I carry the microphone, so it slows you down a bit.

"Friends and family obviously think I've lost it, but it's just a bit of fun."