Tennis officials will dish out stricter punishments for on-court misconduct, the ATP warned players in an internal note on Monday, as the men's governing body also simultaneously reviews its guidelines to clamp down on repeat offenders. 

Australia's Nick Kyrgios was fined $US60,000 ($80,000) for a series of angry outbursts at the Indian Wells and Miami Open events, with many observers saying he should have been disqualified.

German Alexander Zverev was thrown out of a tournament in Acapulco in February after smashing his racquet repeatedly against the umpire's chair following a doubles defeat.

"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 in the note, seen by Reuters.

"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 $US35,000 ($47,000) after his fourth-round loss to Jannik Sinner at the Miami Open during which he criticised the umpire and smashed his racquet.

The incident followed an outburst at Indian Wells where Kyrgios lost his temper after losing to Rafael Nadal, smashing his racquet to the ground, which then bounced up and almost hit a ball boy. He was fined $US25,000 ($33,140) for it.

The Australian earned over $US350,000 ($464,000) in prize-money from the two tournaments after competing in both singles and doubles.

The ATP came under fire for what many pundits and fans perceived to be soft punishments from the governing body and in the note Gaudenzi told players "we all have a role to play to uphold the reputation and integrity of our sport".

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

Reuters