French tennis player Mathieu Montcourt was found dead in front of the door to his ground floor apartment in the Paris suburb of Boulogne-Billancourt early on Tuesday, police said.
The body of the 24-year-old sportsman, currently 119th in the ATP rankings, was found by his girlfriend who then alerted the police.
An autopsy into the causes of death was to be carried out on Wednesday but police said there were no indications that Montcourt had been attacked.
A tennis professional since 2002, Montcourt reached a career best world ranking of 104th in June after qualifying for the main draw at the French Open and reaching the second round where he lost in four sets to Radek Stepanek.
His last tournament was in the Croatian town of Rijeka late June where he reached the semi-final of a Challenger Tour event. His career was badly hit in August last year when he was banned for eight weeks and fined $12,000 for betting on the Internet on the outcome of tennis matches.
Montcourt appealed against the ban and the Lausanne-based Court of Arbitration for Sports reduced the sanction by two weeks citing the small sums of money involved - 192 dollars on 36 games - and the fact that he did not bet on games in which he was playing.