"On Saturday morning we received the terrible and unbearable news of the death of our rider Jimmy Duquennoy," said the team in a statement on Saturday.
"Jimmy died unexpectedly at his home on Friday evening. He was 23. He was the most jovial, the most kind, the most open young man."
Duquennoy had raced with WB's development set-up before joining the pro team in 2016. He was a budding Classics rider and this year made his debut at Paris-Roubaix along with competing at several other of the biggest spring one-day races.
"He had started out in our development team, Color-Code-Aquality Protect before fulfilling his dream by becoming a professional rider at Wallonie Bruxelles in 2016," read the team's statement.
According to the Belgian broadcaster RTBF, who spoke to WB team director Frédéric Amorison, Duquennoy died of a cardiac arrest.
"On Wednesday, we were together on our way back from Germany after the Tour de Munster. He was fine. It's terrible. No abnormality had been detected in the pre-season tests," said Amorison.
Get The Leadout Newsletter
The latest race content, interviews, features, reviews and expert buying guides, direct to your inbox!
Earlier this year the 23-year-old Belgian rider Michael Goolaerts died after suffering a cardiac arrest during Paris-Roubaix, while another young Belgian Daan Myngheer died after a heart attack at the 2016 Criterium International.
A number of riders have had to call time on their careers in recent years due to heart problems, the latest being 20-year-old neo-pro Tanguy Turgis.
Cyclingnews extends its sincere condolences to Duquennoy's family, friends, and teammates.
