Spectators at the men's singles final at the Australian Open tennis tournament have been branded "disgusting" for booing a speech celebrating the coronavirus vaccine roll-out.
On Monday the country's deputy Prime Minister, Michael McCormack branded the behaviour "disgusting" and "un-Australian".
Loud boos could be heard from across the stands at the Rod Laver Arena on Sunday as Ms Hrdlicka said: "With vaccinations on the way, rolling out across the world, it is now a time of optimism and hope for the future".
The jeers continued as she praised the efforts of the State of Victoria government for organising the tournament under extremely difficult circumstances.
The incident coincides with the start of Australia's vaccine roll-out on Sunday.
Mr McCormack responded saying: “I don’t like booing at any event, and certainly any sporting event".
He added: “This vaccine is going to get our country back to some sort of pre-Covid normality."
Djokovic beat Russia's Daniil Medvedev in 7-5, 6-2, 6-2.
The world number one has himself faced criticism after organising the Adria Tour competition - where four players tested positive for Covid, including Djokovic.
He also came under fire for writing to the Australian Open organisers asking them to relax Covid-19 restrictions for players.
It's unclear why Ms Hrdlicka's was jeered but over the past few days protesters have taken to the streets across the country to demonstrate against the vaccine.
Australian Prime Minister Scott Morrison is putting his efforts behind a campaign to boost confidence in the vaccine.
He was among the first to receive his jab in Sydney on Sunday.