Golfing great Rory McIlroy delivered a blow to Ireland's hopes of an Olympic medal on Wednesday when he said he would not be going to the Rio Games over fears of the Zika virus.

"Even though the risk of infection from the Zika virus is considered low, it is a risk nonetheless and a risk I am unwilling to take," the 27-year-old four-time major champion said in a statement.

McIlroy is the latest high-profile golfer to pull out despite the sport making its debut at the Olympics.

Adam Scott, Louis Oosthuizen, Charl Schwartzel, Marc Leishman and Vijay Singh have already said they will not travel to Brazil.