Veranda's Willems-Crelan confirmed to Belgian broadcaster Sporza that the 23-year-old had suffered a cardiac arrest, receiving emergency treatment from medical staff at the scene. TV footage of the race showed Goolaerts lying unresponsive on the side of the road as the peloton passed him.
"It is with unimaginable sadness that we have to communicate the passing of our rider and friend Michael Goolaerts", read a team statement.
Shortly after the race ended, Prudhomme, who is also the Tour de France director, told Reuters: "He has to undergo a scan at the Lille hospital".
The statement added: "For now there will be no further communication as we want to give his close ones time to deal with this bad loss".
Goolaerts finished ninth in the Dwars door West-Vlaanderen one-day race last month and was 20th at Kuurne-Brussels-Kuurne earlier this season.
The race, part of the International Cycling Union World Tour, was won by Slovakia's Peter Sagan with the result now immaterial.
"We thank you in advance for respecting the privacy of his relatives". "I attacked at the right moment and I kept going until the finish".
Goolaerts is the third Belgian rider to die in recent years during a race.
Paris-Roubaix is one of the five Monument classics along with Milan-San Remo, the Tour of Flanders, Liege-Bastogne-Liege and the Tour of Lombardy.
Goolaerts rode in support of cyclo-cross world champion Wout van Aert of Belgium.
"It's fantastic to win Paris-Roubaix".
British Team Sky riders Geraint Thomas and Luke Rowe were both forced to abandon following crashes.