Nick Kyrgios has criticised umpire James Keothavong for failing to control music played at Rod Laver Arena during his Australian Open defeat to Tomas Berdych.
The fiery Australian launched a verbal assault on the official after he heard music coming from the stands during the second set of Friday's third-round match, with Kyrgios unhappy Keothavong did nothing to stop the sounds.
Kyrgios was heard calling the situation "a circus", and said after his 6-3 6-4 1-6 6-4 loss: "Unless I'm hearing things, I thought there was music playing.
"I don't know where it came from. The ref was telling me he couldn't hear it. I could blatantly hear it.
"So if you can start playing tennis when there's music in the background - if that's a new rule - they need to add it to the rule book."
When asked if the noise distracted him, Kyrgios replied: "Not necessarily. It was just strange. He [Keothavong] was telling me he couldn't hear it.
"I don't know, I just thought he might have used the microphone to say 'could you quiet it down'. I don't know. I've never had it happen to me before.
"He didn't tell the crowd to quieten down if it was coming from the crowd, which I think is a fair thing to do if you're in the chair."
Kyrgios had another conversation with Keothavong following the conclusion of the match, leading to the home favourite labelling the umpire "unprofessional".
He added: "I just told him what I thought. I don't think he controlled the match well.
"He let a guy throw a ball back into play, which for me is pretty unprofessional. As I said previously, you know, music playing during points. First time I've ever seen it happen."