The Australian hurled abuse at umpire Fergus Murphy, describing him as "the worst, hands down", during a second-round defeat to Russian Karen Khachanov.

At one stage, Kyrgios violently smashed two rackets away from the gaze of the crowd in Cincinnati as he took a bathroom break, without permission from Murphy, between the second and third sets.

He has had previous run-ins with Murphy and called him "a tool" at the end of Wednesday's match.

The ATP, which runs men's tennis, came down hard on Kyrgios and issued a succession of fines for unsportsmanlike conduct, made up of four separate $20,000 penalties and one for $5,000.

He was given a further $20,000 punishment for verbal abuse, a $5,000 penalty for an audible obscenity and a $3,000 fine for leaving the court without permission.

Kyrgios, who was handed a ban from the tour for eight tournament weeks in late 2016, could find himself suspended again over his conduct.

It could mean the volatile 24-year-old's place at the upcoming US Open is at risk.

In a statement received by Omnisport, the ATP said: "In addition to the on-site fines announced today the ATP is looking further into what happened during and immediately after the match to see if additional action is warranted under the player major offence section of the code.

"That could result in an additional fine and/or suspension."

Kyrgios, who won the Washington Open title earlier this month, lost in three sets to Khachanov.