Arthur Linton's greatest triumph was winning the Bordeaux-Paris race
Drugs were not to blame for the death of a 19th Century Welsh cycling hero, a researcher into his life has claimed.
Arthur Linton died aged 24 in 1896, two months after winning the 360-mile (580km) Bordeaux-Paris race, and the death was suspected to be drug-related.
But after two years of research, Stuart Stanton said he is "convinced" the cyclist, from Aberaman in the Cynon Valley, died from over-exertion.
He is to present his findings in a talk at the Cynon Valley Museum on Saturday.
Last week, Rhondda Cynon Taf council announced Linton would be among 30 people, places or events to be marked with a series of blue plaques.
Mr Stanton, who originally from Ebbw Vale and the organiser of the Junior Tour of Wales, said he was "convinced there was nothing going on".
"We've had a story that's been mistreated for the last 100 years."
"I hope the misinterpretation of this story will be thoroughly put to bed and he's recognised for what he was - an enormous, ground-breaking champion."
"He actually died of typhoid and it seemed the typhoid was brought on by over-exertion."
Arthur Linton became famous at home and in France for his success in the early days of the competitive cycling, when the sport was more popular than rugby.
He was born in 1868 in Langport in Somerset and moved to south Wales with his family when he was three.
In 1893, he broke the world one-hour unpaced record at a cycling track in Cardiff, covering more than 23 miles in one hour.
But his achievement was never recognised officially.
In 1896 he won the Bordeaux-Paris race, then regarded as the "world championship" of cycling, according to Mr Stanton.
After being forced to retire from races in Paris and London, he returned home to Aberaman and died two months later.
Mr Stanton also believes Linton's victory may have inspired the French cyclist Henri Desgrange to found the Tour de France in 1903.
"At the finish Henri Desgrange saw the figure of Linton coming over the line and to say he was on his last legs was a bit of an understatement."
Rhondda Cynon Taf's cabinet member for culture and recreation Councillor Robert Bevan said: "Arthur Linton's life was quite remarkable and I'm pleased to see that his many achievements are still being celebrated more than a century after his death.
"His rags to riches story will undoubtedly inspire all those who hear it because Linton was undoubtedly one of the county borough's greatest sporting heroes."
Stuart Stanton's talk on Arthur Linton will take place at the Cynon Valley Museum and Gallery at 1400 GMT on Saturday.