Tennis officials will hand out stricter punishments for on-court misconduct, the men's governing body has said.

Australian Nick Kyrgios was fined a total of $60,000 (£45,700) after the 26-year-old's outbursts at Indian Wells and the Miami Open earlier this year.

German Alexander Zverev was also thrown out of the Mexican Open after hitting the umpire's chair with his racquet.

In a letter seen by Reuters news agency, the ATP said the incidents "shine a bad light on our sport".

"Effective immediately and as we head into the clay court swing, the ATP officiating team has been directed to take a stricter stance in judging violations of the code of conduct," ATP chairman Andrea Gaudenzi said.

"Additionally, we are also undertaking a review of the code, as well as the disciplinary processes, to ensure that it provides appropriate and up-to-date penalties for serious violations and repeat offenders."

Kyrgios was fined $35,000 (£26,600) after criticising the umpire and smashing his racquet in his fourth-round loss to Jannik Sinner in Miami, and then $25,000 (£19,000) at Indian Wells after again smashing his racquet - almost hitting a ball boy in the process.

Meanwhile, world number three Zverev, 24, was given a suspended eight-week ban after attacking the umpire's chair with his racquet in Acapulco.

Gaudenzi told players they "all have a role to play to uphold the reputation and integrity" of tennis.

"The first three months of the season have seen an unusual frequency of high-profile incidents involving unsportsmanlike conduct," the former player added.

"This conduct affects everyone, and sends the wrong message to our fans, especially young fans."