PARIS (AP) — French tennis player Mathieu Montcourt, who was recently banned for betting on matches, has died. He was 24.

The French tennis federation said Tuesday that Montcourt died overnight but the cause of death is not yet known, and an autopsy will be conducted.

French media reported the 119th-ranked Montcourt was found dead by his girlfriend in the stairwell of his Paris apartment. In May, Montcourt was handed a five-week ban and fined $12,000 for betting on other matches. That ban took effect Monday.

“It is with great sadness that the French tennis federation has learned of the sudden death of Mathieu Montcourt,” the French tennis federation said. “Mathieu was an enthusiastic young man, passionate, very endearing, and extremely appreciated for his kindness and politeness.”

Four-time French Open champion Rafael Nadal grew up playing against Montcourt on the junior circuit.

“This morning I woke up with one of the worst news anyone can receive,” Nadal said on his Web site. “I heard about the death of our friend Mathieu Montcourt. I am still under shock for this. I can’t believe it.”

French tennis federation’s technical director Patrice Dominguez told The Associated Press on Tuesday that Montcourt’s girlfriend became alarmed when Montcourt failed to arrive.

“She was with a friend in Mathieu Montcourt’s apartment,” Dominguez said. “They came out after a while, having left him messages, and noticed that he was lying on the floor next to his bike … They called the (ambulance), but unfortunately he was already dead.”

Montcourt complained during the French Open that the punishment was too harsh, saying that he never bet more than $3 at any time, and never on his own matches — a fact confirmed by the ATP, which oversees the men’s Tour.

The Court of Arbitration for Sport said Montcourt had wagered a total of $192 on 36 tennis events in 2005. It reduced his suspension on appeal from eight weeks to five.

A moment of silence was planned before the first match Tuesday at The Hall of Fame Tennis Championships in Newport, R.I.

“It’s really sad. I practiced with him for the first time at Roland Garros,” said Fabrice Santoro, the two-time Newport defending champion.

ATP board member Justin Gimelstob said, “The tennis community is a tight group and to lose one of our players at such a young age is really difficult for everyone.”

The issue of betting in tennis drew increased attention from the sport’s governing bodies after an online bookmaker voided all wagers on a 2007 match involving Nikolay Davydenko. About $7 million was bet — 10 times the usual amount for a similar-level match — and most of the money backed Davydenko’s lower-ranked opponent.

Davydenko was cleared in September after a yearlong investigation.