Australian Nick Kyrgios was involved in a fresh dispute after being accused of swearing at the BNP Paribas Open in California on Saturday.
At 2-2 in the second set of his second-round defeat by Spaniard Albert Ramos, the umpire said Kyrgios had used foul language and docked the player a point.
"You used the F word," explained French official Damien Dumusois.
Kyrgios protested and, after briefly taking a seat in the crowd, he approached the umpire.
"I didn't say anything," he said.
Dumusois replied: "Nick. You know we are strict on the F word...I have a report from an official. I trust him".
Ramos went on to win the match 7-6 (4) 7-5 on an outside court at Indian Wells.
In Canada last August, Kyrgios incurred the wrath of the ATP after a courtside microphone picked up a comment directed at opponent Stan Wawrinka.
The comment, about Wawrinka's girlfriend, earned Kyrgios a suspended 28-day ban and $25,000 fine.
He had already been fined the on-site maximum of $10,000 for the offence and a further $2,500 for remarks directed at a ball person.
Last week Kyrgios became embroiled in another spat when Bernard Tomic accused his countryman of feigning illness to miss a Davis Cup tie that Australia lost to the United States.