A selfless man ignored his own pain and carried an injured runner across the London Marathon finish line.

Alex Lacey, 36, of Bushey, ran the London Marathon last weekend after CLIC Sargent, the cancer support charity, asked him to take part as a number of their runners pulled out.

With only three weeks to train, Mr Lacey injured his calf but that did not stop him.

According to Mr Lacey he began struggling around the mile 18 point but he had to finish the race and the support of the crowd kept him going.

At mile 24, Mr Lacey pulled up and began stretching. He noticed a man grabbing on to the railings trying to hold himself up.

The man’s legs were like jelly and he could not carry his own body weight, according to Mr Lacey.

Mr Lacey said: “All he kept saying was ‘he can’t not finish’ and it just hit me really hard.

“For anyone to get to mile 24 needs to finish the race. The paramedics said they could take him away but he wouldn’t finish and wouldn't get his medal.

“I grabbed hold of him and carried him in a fireman’s lift. I didn’t want him to wake up the next day and not have finished it.

“Everyone runs for a good cause and everyone should finish. That is why I wanted to help him.

“I did it for him and me. I woke up the next day and had the best feeling in my life knowing what I had done.

Mr Lacey began carrying the injured runner the rest of the way.

At mile 26, he began to struggle under the weight and his legs were in a lot of pain and were weak.

He had to stop and put the man down due to the pain in his legs. Another runner, William Brindley, stopped and helped carried the man with Mr Lacey.

Around 600 metres to the finish line another man helped the two runners and grabbed hold of the man’s legs.

All three runners wanted him to make it across the finish line.

Mr Lacey said: “How I got from mile 24 to mile 26 carrying him is hard to believe but the cheering and supporting from the crowd really motivates you.

“The crowd at London are unbelievable. Everyone wants you to get across the finish line.

“I think it was the crowd who got me through to the end of the race.”

Mr Lacey, who has completed the London Marathon before, was running for his dad who died of cancer.

He promised his dad he would run the marathon for him and he was hoping to beat his previous time of 3 hours and 10 minutes.

However, Mr Lacey said stopping to help the injured runner was the right thing to do.

He said: "Everyone asks you how quickly you want to finish the race but they don't know how hard it is. I finished the race in 4 hours and 35 minutes.

"But helping the other runner was the best thing I could have done."

As soon as the three men crossed the finish line, the St John’s Ambulance took the runner away to be looked after.

Mr Lacey has not heard from the runner yet and is hoping someone will contact him to let him know whether the runner is ok.

To donate to Mr Lacey's page follow the link.