The runner who died during the London Marathon was named yesterday as a popular Army captain.

David Seath, 31, collapsed just three miles short of the finish line from a suspected cardiac arrest.

Dozens of police and paramedics rushed to his aid and took him to St Thomas' Hospital but he was pronounced dead shortly afterwards.

His devastated friends are now planning to walk the final three miles and complete his run in his honour.

A fundraising page has also been set up in his memory by fellow Army officer and close friend James Walker-McClimens, 34.

James said: "He was three miles short of the finish line and collapsed on Upper Thames Street.

"His friends and colleagues are planning to complete what he started, in his honour.

"We will walk as one, the final three miles of the marathon, starting where he fell.

"We're raising money for Help for Heroes, a cause he ran and died for.

"He was our friend and hero."

Captain Seath, from Cowdenbeath in Fife, Scotland, was a Fire Support Team Commander with the 29 Commando Regiment Royal Artillery.

He gained two Masters degrees from the University of Aberdeen before competing his Army training at Sandhurst in 2010.

It is understood he was currently based in Plymouth, Devon, and he had served in Afghanistan, in the Nahri Saraj district of Helmand province.

He had done other charity work and worked with groups which helped visually impaired Army veterans, including Royal Blind and Scottish War Blinded.

Before his death he raised around £500 for Help for Heroes by entering the London Marathon and in his final online message thanked his supporters.

Writing on Saturday morning, he said: "A big thank you to everyone that has been so generous and sponsoring me for tomorrow.

"I am sure H4H will be equally as appreciative.

"Every penny counts and to have broken the £200 mark with your help is very special.

"Thank you all so much."

His brother Gary is part of the marketing team at the Royal Blind and Scottish War Blinded charities.

Gary wrote recently on the charity website: "My brother is a Major in 29 Commando Regiment Royal Artillery, which has provided considerable insight into military life and greatly assists me in terms of engaging with Scottish War Blinded members."

One of the donations to his JustGiving page came from his niece, Maisie Calcutt, who gave £10.

She wrote: "You're my hero Uncle Dave, lots of love Maisiexx"

Earlier in April, Captain Seath had written: "Not long to go now until I run the London Marathon in aid of Help For Heroes.

"Please give generously to a charity that does so much for the armed forces community. Thanks."

Since he passed away, a further £700 has been raised, but this total is expected to rocket throughout the day.

The previous death in the London Marathon was in the 2012 event when Claire Squires, 30, from North Kilworth, Leicestershire, died.

A fund-raising page set up in her memory raised almost £1million for the Samaritans.

David's friends have asked that any donations be made to this page - https://www.justgiving.com/H4HeroDavidSeath