After his 3-1 defeat to Rob Cross on Thursday night, five-time world champion Raymond Van Barneveld revealed that he had tested positive for COVID-19.
Barneveld stated he had no symptoms during his second-round tie but did say that he began to feel unwell in his post-match interview, which later resulted in a positive test.
A Professional Darts Corporation spokesperson has since commented: "We have been made aware of Raymond's positive test and send him our best wishes for a speedy recovery.
"We are following approved protocols and have appropriate regulations in place around the William Hill World Darts Championship, one of which is that all players and staff must produce a negative Covid test result on their return to the event after the Christmas break."
The 54-year-old Dutchman announced to his fans on Twitter that he had contracted the virus.
He said: "During the match I didn't have any symptoms, but afterwards I started to realise that I was developing a shortness of breath and fever.
"I directly called my manager Ben De Kok and he advised to go straight to my hotel room and to not give interviews in order to avoid any risk.
"At the moment I do suffer from fever and serious tiredness. The upcoming days I will stay in quarantine in London.
"We already spoke with Rob Cross and the PDC about the current situation. Stay safe."
Van Barneveld, one of only three players to win the world crown five times, retired in 2019, but returned to the sport last year and was attending his 29th World Championship.