The President of the World Anti-Doping Agency (WADA) Witold Bańka has expressed concern at the outcome of the Salwa Eid Naser whereabouts case – which cleared the Bahraini sprinter of any wrongdoing.
Beijing 2008 Olympic racewalking champion Valery Borchin rejected a return to competition after serving an eight year doping ban.
Daniel Wanjiru, who won the London Marathon in 2017, has been banned for four-years for an Athlete Biological Passport (ABP) violation.
Timofey Lapshin has denied violating anti-doping rules and has vowed to challenge his suspension from biathlon competition.
The World Anti-Doping Agency (WADA) has published a redesigned List of Prohibited Substances and Methods for 2021.
Sports doctor Mark Schmidt has confessed to the use of illegal drugs and blood doping in Germany and Austria, having been involved in scandals in cycling and winter sports such as skiing.
Kenyan President Uhuru Kenyatta has admitted the spate of doping cases among his country's athletes is "troubling" as he called for the Sports Ministry to enhance its education to prevent further violations.
A criminal investigation has been launched into alleged doping during this year's Tour de France, with a doctor and physiotherapist reported to be in police custody.
A co-defendant in the Operation Aderlass doping trial has admitted helping doctor Mark Schmidt administer blood transfusions to athletes.
The trial of Mark Schmidt has begun in Munich, with the German doctor accused of being part of an international blood doping ring.
Witold Bańka has claimed the participation of athletes from the United States in major events, such as the Olympic Games, could be threatened should the country follow through with its warning to withdraw funding from the World Anti-Doping Agency (WADA).
Swiss cyclist Kevin Winter has been given a four-year doping ban after he tested positive for three prohibited substances.
Ukraine's canoe sprint paddler Oleksandr Senkevych has been handed a four-year ban after testing positive for a banned substance last year.
Indian wrestler Narsingh Yadav has stated that he aims to have redemption at the Tokyo 2020 Olympics on the return from his four-year doping ban.
Former tennis player Mariano Puerta of Argentina has admitted lying to the Court of Arbitration for Sport (CAS) to get his doping ban reduced.