After claiming the biggest payday in women's tennis history, Elena Rybakina refused to pose for a photo with WTA Tour chief executive Portia Archer.

Rybakina, the 2022 Wimbledon champion, beat world number one Aryna Sabalenka in straight sets at the WTA Finals on Saturday.

But the Kazakh 26-year-old, who climbed to fifth in the world following the victory, which secured £3.98m in prize money, stood separate from Sabalenka and Archer during the post-match celebrations, despite being asked to join them.

Why?

Rybakina declined to say what her motive was, although the incident comes at the end of a season where the WTA issued a ban to her coach Stefano Vukov.

Vukov was suspended earlier this year after being found to have breached the WTA's code of conduct, following an independent investigation into his behaviour towards the player.

At the Australian Open in January, Rybakina criticised the WTA, saying she did not "agree with a lot of things" the governing body was doing in regards to her working relationship with Vukov.

Rybakina has maintained that she was never mistreated by the 38-year-old Croat.

Vukov denied any wrongdoing and, having had his ban lifted in August, was present as Rybakina triumphed at the tour's season-ending tournament.

Concerns have been raised about Vukov's behaviour towards Rybakina over the past few seasons - most notably from coach and commentator Pam Shriver.

Shriver, a winner of 21 Grand Slam doubles titles, has called for safer tennis coaching at all levels of the sport.

Amid scrutiny over the manner in which Vukov spoke to Rybakina on and off court at tournaments, Shriver posted on X in 2023 that she hoped Rybakina "finds a coach who speaks and treats her with respect at all times".

Following Rybakina's triumph at the WTA Finals, Shriver wrote: "Imagine winning more prize money in one tournament than the entire 'Original 9' over their collective careers, then dissing [the] WTA CEO because the CEO has tried to ensure stronger safeguards in your sports… it's hard to imagine."

Rybakina had worked with Vukov since she was a teenager before briefly ending the partnership before last year's US Open.

However, when she decided in January that she wanted Vukov to rejoin her team, his provisional suspension meant he was denied accreditation at the Australian Open.

Speaking in February, Rybakina said she was in contact with Vukov and he was still helping her with "a lot of things, on the court, outside of the court".

Asked on Sunday whether she had held reconciliation talks with the WTA following Vukov's return, Rybakina told AFP: "I think we're all doing our job and we had the opportunity to have conversations, but in the end it never happened.

"So we're all doing our job and I think we're going to keep it this way."

But Rybakina said that she preferred to keep the reason for not joining the ceremonial photo with Archer between them.

The WTA did not want to comment on the matter when contacted by BBC Sport.

BBC Sport has also approached Rybakina for comment.