Djokovic, speaking to reporters as he prepared to defend his US Open title, said players who have bemoaned a lack of transparency in the Sinner case make a valid point.
Tennis world number one Jannik Sinner has been cleared of any wrongdoing after twice testing positive for a banned substance earlier in the season, the International Tennis Integrity Agency (ITIA) announced Tuesday.
Top Indian sprinter Dutee Chand has been banned from competition for four years after she failed two doping tests, local media reported Friday.
US swimming legend Michael Phelps has spoken of his frustration at the possibility rivals were using drugs at last year's Rio de Janeiro Olympics.
Maria Sharapova said Wednesday she refused to feel sorry for herself during her doping ban, occupying her time by studying at Harvard, writing a book and even learning how to box.
Doha's anti-doping laboratory has had its accreditation suspended for four months after it failed to comply with international standards, the World Anti-Doping Agency (WADA) says in a statement.
Mo Farah, Rafael Nadal and Justin Rose are among athletes targeted in the latest leak of confidential medical documents that the world anti-doping agency (WADA) says were hacked by a Russian cyber espionage group.
Brazilian cyclist Kleber Ramos and Chinese swimmer Chen Xinyi are disqualified from the Olympic Games for having failed doping tests, the Court of Arbitration for Sport (CAS) says.
Brazilian police arrest two US swimmers and a top International Olympic Committee official as scandal overshadows the Rio Games.
Russia should be banned from athletics competition, a World Anti-Doping Agency commission report has recommended.
Jamaican sprint star Usain Bolt expresses his sadness that doping issues are the talking points before world championships at Beijing.
Detectives claim detention of 12 members of doping gangs including two ringleaders of such rackets from Dhaka.
Pakistan spin bowler Raza Hasan has been banned for two years after failing a doping test, the country's cricket board says.