Serbian tennis player Novak Djokovic, who is currently ranked number one in men's singles tennis by the Association of Tennis Professionals, said he has tested positive for COVID-19.
A statement from his staff has been shared on Twitter.
This comes after Grigor Dimitrov, Borna Coric and Viktor Troicki all tested positive for coronavirus after playing at Adria Tour event in Zadar, Croatia.
The final of the tournament was cancelled by organisers "as a precaution and to protect the health of all participants and visitors".
"I am extremely sorry for each individual case of infection. I hope that it will not complicate anyone's health situation and that everyone will be fine. I will remain in self-isolation for the next 14 days, and repeat the test in five days," Djokovic said in his statement.
The Adria Tour event, which was organised by Djokovic, took place weeks after both Serbia and Croatia had eased their lockdown measures. In view of this, athletes did not have to observe social distancing rules, and the public was allowed to attend matches.