Australia's world number one golfer Jason Day is out of the Rio Olympics, citing Zika virus fears.
He is the third Australian golfer, alongside Adam Scott and Marc Leishman, to withdraw from the Games.
The mosquito-borne virus causes flu-like symptoms in adults, and rarely requires hospital treatment. But the risk is significant for pregnant women; the virus can cause severe birth defects, including microcephaly, in newborn babies.
The 28-year-old posted a statement on Twitter.
The withdrawal of the leading golfer will likely be a huge disappointment those who pushed for the sport's reinstatement to the Olympics, 112 years after it last appeared on the program at the St Louis 1904 Games.
The Rio Organising Committee has been besieged by Zika, security issues, economic and political turmoil in the lead-up to the Olympics which run from August 5 to 21.
When golfers first started dropping out of the Olympics, they didn't overtly mention Zika, instead citing "scheduling" and "family concerns".
But as the Games draw closer, sportspeople withdrawing from selection are naming Zika as the primary barrier.
Rio has built a new world class golf course especially for the Olympics. It is situated in former marshland in the suburb of Barra da Tijuca, close to the main Olympic Park precinct. It's probably not the most difficult place in Brazil to find a mosquito.
On the sporting front, the focus now turns to who will represent Australia in Rio in men's golf. With the withdrawal of Australia's three top ranked golfers (Day, Adam Scott and Marc Leishman), the focus now turns to lesser known players Scott Hend (world ranking 75), Marcus Fraser (81) and 2015 Australian Open winner Matt Jones (85).
The top two ranked players are eligible for selection.