The Australian has been highly critical of his rivals in the top echelons of men's tennis, after Novak Djokovic and a host of others were pictured partying during the ill-fated Adria Tour. 

During the tournament, played in front of crowds and in defiance of the strict Covid-19 measures being undertaken by other sports, Djokovic and a number of rivals tested positive for the illness. 

Zverev returned a negative test, before insisting he would self-isolate for 14 days regardless. But images of the German partying in a crowded bar have provoked another strong reaction from a fed up Kyrgios.