Women's Tennis Association chair Valerie Camillo has apologised to Jessica Pegula and said the live-streaming of private comments to her coach about fellow player Mirra Andreeva was "regrettable and unacceptable".

American Pegula called Andreeva a "diva" in a private conversation with her coach after a practice session for the WTA Tour Finals on Wednesday.

However, the comments were aired on a live stream after the WTA failed to tell players there were microphones on practice courts.

World number five Pegula called the incident "unfortunate" and said the WTA players' council supported players' calls for more privacy.

Camillo said that all audio recording equipment in practice areas had since been removed as "clearly there was a failure in our technical execution and monitoring".

"I want to specifically apologise to Jessica Pegula and [coach] Mark Knowles," she added.

"What happened was regrettable and unacceptable. Jess is one of the WTA's best advocates and biggest stars. She does not deserve this distraction."

Pegula was also heard saying French Open champion Andreeva "needs to be humbled" and her coach Conchita Martinez encourages her behaviour.

A representative for Pegula said she had been in direct contact with those involved and had been "completely unaware" the conversation could be heard by courtside microphones.

None of the players were asked about the incident in the pre-tournament news conference at Indian Wells on Friday, but Pegula did address it in an interview with ESPN.

"I think it's something that we have fought a lot over the last couple years as there's a lot more surveillance and audio and access to the players at tournaments than there has been in the past," she said.

"I know for broadcasting that it's great for fans, but I think we've seen a couple incidents now throughout the year, [the] last couple of years really, where it just seems highly unnecessary.

"I think [this will] definitely reignite the topic and, hopefully, we can unfortunately use this incident to keep pushing for more player privacy."

Pegula's compatriot Coco Gauff called for more privacy after she was captured in the players' area smashing a racquet following a defeat by Elina Svitolina in the Australian Open quarter-finals in January.

At the same major, six-time Grand Slam champion Iga Swiatek said players were being watched "like animals in the zoo" by behind-the-scenes cameras.

YouTube streams of Wednesday's practice sessions at Indian Wells have since been removed by the WTA, but the footage had already been shared on social media.

Referring to the incident in California, where the season-ending WTA Finals are being held, Camillo added: "The WTA is sensitive to player privacy and has policies and procedures in place to balance players' needs for safe spaces with opportunities to bring fans closer to the game.

"There was a lack of advanced notice and clear signage to assist players about the recording equipment operating in the area."