Mr Mileson regularly joined Gretna fans on the terraces
Former Gretna FC owner Brooks Mileson has died in hospital after being found unwell in the garden of his home.
Ambulance crews are reported to have been called to Mr Mileson's home at Blackford in Cumbria on Monday morning.
Mr Mileson, 60, was taken to Cumberland Infirmary in Carlisle where he later died.
The multi-millionaire took Gretna to the Scottish Premier League before illness led to him withdrawing his financial backing, and the club folded.
Mr Mileson had been in poor health for a number of years before a deterioration in his condition led to him pulling his money out of the tiny south of Scotland club, who had been languishing in the lower reaches of the English system before he bought them and successfully applied for a place in the Scottish League.
The chain-smoking entrepreneur was famously eccentric, wearing his hair in a ponytail and mingling with fans on the terraces at matches as he and his club lived the dream.
Gretna lived up to their home town's romantic reputation as they rapidly rose to the Scottish Premier League - albeit for only one season - and also reached the Scottish Cup Final in 2006, where they lost on penalties to Hearts.
They appeared in the Uefa Cup last season, where they were comfortably defeated by Derry City.
Earlier this year, Mr Mileson was admitted to hospital with a brain infection and although he was released, neither he nor Gretna ever fully recovered.
Mr Mileson withdrew his financial backing from the club, leaving several players redundant, and a long list of creditors.
Gretna were relegated from the SPL and eventually went out of business, with their place in the Scottish Football League being taken by neighbours Annan Athletic.
A new club, Gretna 2008, was formed from the ashes of the original Gretna FC, and currently plays in the East of Scotland league.
Dumfriesshire MP David Mundell said: "This is very sad news and my thoughts are with Brooks' wife and family.
"Brooks was a larger than life character and although his time at Gretna FC was a rollercoaster ride he certainly brought excitement and colour into our local community and he will be remembered.''