Nobody in the Tour de France convoy was surprised when Tom Boonen, Belgian national champion, triple champion of Paris-Roubaix and enfant terrible of the professional peloton, failed to start the 15th stage of the race, from Pontarlier to Verbier.

Boonen, who tested positive for cocaine last spring, had been declared persona non grata by the Tour organisation, but a last- minute appeal to arbitration saw him take to the start line in Monaco. Despite overturning the ban, tales of his excesses have become a regular theme in Belgian coverage of this year’s Tour.

The 28-year-old had been expected to challenge strongly for the points classification, but Boonen’s form has been so poor throughout the Tour that he has struggled to even contest a single sprint. Instead, he has spent most of the race at the rear of the peloton, plagued by crashes and punctures.

Two days after winning the Belgian title and shortly before the Tour began, he was captured by Belgian paparazzi in a dishevelled and drunken state, snatching food from the plates of customers in a late night burger bar. Further allegations in the Belgian media of romantic entanglements saw his partner, Lore, exit the family home.

However, shortly before the Tour start, his wife had returned. “At the time (of the Tour start) I had the media on my back over the cocaine test, but the most important thing for me is not to lose my partner,” he said.

Although the official explanation for his abandon from the race was fever, Boonen had already acknowledged that he has been battling his demons since the Tour began over two weeks ago. “After everything that has happened, if Lore left me I’d have to give up racing,” he said.

Boonen, winner of the Tour’s points classification in 2007, is not the first troubled Belgian champion. Freddy Maertens, a former green jersey wearer and more recently Frank Vandenbroucke, once seen as a contender for Tour victory, both struggled with similar problems during their careers.

Any sabbatical from the European racing scene appears likely to be brief, however. According to his team, Boonen’s next major objective is likely to be the Tour of Spain.