Grigor Dimitrov on Sunday said he had tested positive for COVID-19, leading to the cancellation of the ongoing Adria Tour in Croatia, which features world No. 1 Novak Djokovic.

The 29-year-old Bulgarian withdrew from the exhibition tournament after losing to Borna Coric on Saturday, complaining of feeling unwell.

"I want to reach out and let my fans and friends know that I tested positive back in Monaco for COVID-19," former world No. 3 Dimitrov wrote on Instagram.

"I want to make sure anyone who has been in contact with me during these past days gets tested and takes the necessary precautions.

"I am so sorry for any harm I might have caused. I am back home now and recovering. Thanks for your support and please stay safe and healthy."

Later on Sunday, the final between Djokovic and Russia's Andrey Rublev was immediately canceled as a precaution. 

"This is the best possible decision. We have to take care about security of all involved," former Wimbledon champion and event's director Goran Ivanisevic said.

"Those who were in contact with Grigor will be tested. We are waiting for instructions of relevant bodies," he added.

Last weekend, Dimitrov, 29, took part in the Adria Tour event in Belgrade with Djokovic, world No. 3 Dominic Thiem and Alexander Zverev, ranked 17. 

The Adria Tour, a Balkan charity event organized to fill the gap in the virus-hit tennis calendar which has been on ice since mid-March, has copped widespread criticism over a stark lack of social distancing between fans, players and officials. 

(With input from agencies)