The professional chef collapsed at the 22.5 mile mark and although he received immediate medical attention at the scene from race doctors, he later died in hospital.
The 29-year-old, who was from the Lake District, featured in the 2017 series of ‘Masterchef: The Professionals’, inspiring viewers with his Nutritional Gastronomy movement and forward-thinking ideas.
Ahead of Sunday’s race - the hottest on record - he tweeted a photo of himself and fellow chef Tom Peters, who was also running, captioning it: “Let’s do this.”
He was running for The Brathay Trust and in memory of his father, Martin, who died in the summer of 2016.
He added: “As many of you know, I lost my father Martin 18 months ago suddenly. The past year & a half have been the toughest of my life but his spirit and energy live on in me.
“He always spoke to me so passionately about the event and the charity.
“He was the most inspirational man in my life and was the one who said - ‘Go on, why don’t you give it a go? I know you can do it!’
“I am honoured to run on behalf of such an amazing charity. Although he won’t be there in person, I know he will be there in spirit and I will be running for him.”
It was Matt’s second marathon this month, having completed the Manchester Marathon on 8 April in under three hours.
After the Manchester event, he shared a picture of him celebrating on Instagram, which he captioned: “Amazing day @manchestermarathon perfect conditions, great support. Thank you SO much to everyone who has sponsored me, my dad and @brathaychallenges.”
Matt’s chosen charity, The Brathay Trust, inspires vulnerable young people to make positive changes in their lives.
Since news of his death was made public, Matt’s JustGiving page has been inundated with donations, with the total tripling in an hour. It now stands at £80,000.
The charity paid tribute to Matt on Monday (23 April) afternoon, with a statement that read: “We are devastated by the news of the death of Matt Campbell, who was participating in the 2018 Virgin Money London Marathon yesterday whilst raising funds for Brathay Trust.
“Matt and his family have been tireless in supporting the work of Brathay Trust and our thoughts and prayers are with them at this terrible time.
“Matt became involved with Brathay Trust through his father Martin, who was a key member of the team delivering the Brathay 10in10 (10 marathons in 10 days) until his untimely death in the summer of 2016.”
After finishing second on ‘BBC Young Chef Of The Year’ at the age of 20, Matt honed his culinary skills by working in Michelin starred kitchens, before leaving the UK restaurant scene to work in the French Alps as a private chef, cooking for VIP guests.
He spent the next eight years cooking and travelling the world to expand his knowledge and skills across Europe, India, Thailand and South America, before returning to the UK and entering ‘Masterchef: The Professionals’.
During his time in the competition, top chef Marcus Wareing described his signature dish of Cod Cheeks, Spirulina, Kale & Kombucha as the best he’d ever tasted on ‘Masterchef’.
In a statement, a ‘Masterchef’ spokeswoman said: “We are shocked and saddened to hear the news about Matt Campbell, one of our talented contestants from last year.
“It was a privilege to have him on the show. He will always be remembered for producing for some of the most innovative and groundbreaking food that we saw on the series.
“From the whole MasterChef team, our sincere condolences and thoughts are with his family and friends.”
Helen Hokin, who looked after his PR, told the BBC: “He was a lovely, kind-hearted and down-to-earth man. I believe he was poised to become the next great innovator in British food.
“He was in the middle of a roadshow tour and he had such a way with inspiring young chefs. This is so sad.”
Journalist and restaurant critic Grace Dent was one of the first to pay tribute to Matt on Instagram, writing: “Brilliant, clever, funny, talented as hell Matt. It is unfathomable.”
Food critic Jay Rayner also paid tribute, tweeting: “Awful news. I presented Matt with an award for outstanding achievement at last month’s Cumbria Life Food and Drink Awards. He was clever and, as my colleague @gracedent said in @obsefood only yesterday, hugely creative and innovative. My thoughts are with his family.”
The exact cause of death will be established by later medical examination.
You can make a donation to The Brathay Trust on Matt’s JustGiving page here.