London - Roger Federer has vowed to investigate the ATP's controversial decision to reject an offer to increase prize money at the Indian Wells tournament.
The issue of prize money has been a hot topic for the last 12 months as stars like Rafael Nadal and Novak Djokovic push for the four Grand Slams to raise the financial rewards on offer.
As president of the ATP players' council, Federer has been keen to ensure any increase in prize money is spread equally among the lower-ranked players as well as the leading names.
And the players, who had talked at times of considering strike action to make their point, appeared to be winning the battle as Wimbledon and the Australian, French and US Opens all opened up the coffers to improve prize money this year.
But the ATP delivered a surprise blow to the cause earlier this month when it was revealed that organisers of the Indian Wells event in California - one of the ATP's flagship Masters 1000 tournaments - had been snubbed when they offered to improve the total prize money pot by $1.6m, meaning an extra $800 000 each for the men's and women's competitions.
The decision was reportedly taken because the tournament wanted to give more to those losing in the earlier rounds in contravention of ATP rules, but many players are said to be furious about the move and Federer plans to ask questions in a bid to resolve the problem.
"For me, I was a bit surprised to hear that," Federer said after his win over David Ferrer at the ATP Tour Finals in London on Thursday.
"Obviously, I wasn't in the room when everything went down because it's at the board level, at the CEO level.
"What I can tell you is I will investigate and make sure that the decision they've taken is, indeed, the right one.
"If it's not, then obviously we need to talk about it and what we can do in the future. It's an important issue."
Former Wimbledon finalist Tomas Berdych, the Czech fifth seed at the Tour Finals, also took issue with the ATP's decision when asked about the situation earlier in the week.
"That's what we all looking for. If there is someone who is able to increase it, bring something more to us players, then I don't see any reason why someone could be saying, 'No, it's not good idea'," Berdych said.
"I don't see any reason why there should be a problem with that. That's probably the goal of all of us. I mean, if there is someone who is able to do it, why to say no?"