Marc Sutton was riding along a popular mountain bike track Saturday evening when he was shot and killed by a hunting party, Sky News reported.
The name of the victim has not been released but he is believed to be a 34-year-old restaurateur implanted nearby.
The French town of Montriond has temporarily banned all hunting as officials investigate the gunman on suspicion of aggravated manslaughter.
Mr Sutton was originally from Wales and owned a local health food restaurant called Wild Beets Kitchen in ski resort Les Gets with his partner Jo.
Mr Sutton (left) was shot by a 22-year-old hunter who taken to hospital suffering severe shock.
He was cycling on a proper mountain bike trail and had been wearing "a brightly-coloured helmet and coloured mountain bike", according to prosecutor Philippe Toccanier.
The shooter has not been arrested, but a manslaughter inquiry has been opened by the prosecutor in Thonon-les-Bains, in cooperation with the local gendarmerie.
Georges Lagrange, the mayor of Montriond, suspended hunting yesterday until the end of the season next month.
"People will pay more heed to the times and zones of hunting, and stick to times and areas where they know they are safe, and hunters can hunt with less likelihood of these bad accidents".