Eddy Merckx is in hospital with a head injury following a crash while riding his bike on Sunday, according to Belgian newspaper Het Nieuwsblad.
The five-time Tour de France champion suffered a "serious head injury" and was "rushed to hospital" in Dendermonde, near Gent.
According to the paper, the 74-year-old was treated with caution, given he uses a pacemaker, but was transferred to a regular ward on Monday after further examination.
Merckx was riding with friends on Sunday when the accident occurred.
"I was in contact with his wife Claudine last night", Merckx’s friend Paul Van Himst told Belgian broadcaster, Sporza. "According to her, it is, all in all, OK. Today, new tests are planned."
Merckx is widely regarded as the most successful cyclist of all time, winning the Tour de France and the Giro d’Italia five times, as well as 19 Monuments in a career that ran from 1965 to 1977.
He worked with Tour de France organisers ASO until 2017 and his legacy was celebrated at the Grand Depart of this year’s Tour de France in Brussels, on the 50th anniversary of his first yellow jersey.
Merckx was fitted with a pacemaker in 2013 after being diagnosed with cardiac arrhythmia, something he may well have had during his riding career.
Merckx is not the only prominent former rider in hospital. Eighty-three-year-old Raymond Poulidor – eight-time podium finisher at the Tour – has spent the last few weeks in hospital, but appears to have shown some improvement in recent days, according to the French press.
Meanwhile, Roger De Vlaminck – a four-time winner of Paris-Roubaix during the 1970s – was admitted to hospital on Saturday due to a fever, according to the Belgian press, but is also now feeling much better.