Roger Federer has finally weighed in on Serena Williams' US Open sexism storm.

Tennis legend Roger Federer has spoken out about Serena Williams’ US Open sexism saga, suggesting the incident could lead to change.

Williams’ accused umpire Carlos Ramos of racism and sexism after her US Open women’s final loss to Japan’s Naomi Osaka, causing divide within tennis as well as with wider sports fans.

In typical Swiss fashion, Federer remained impartial when speaking about the issue to Texas TV station KVUE at a charity event for former rival Andy Roddick.

“It’s interesting but I think it’s important to look at it. Every umpire has their own style, it’s just how it is in any sport,” he said.

“In tennis you might have an umpire that gives more coaching violations and another guy goes more to time violation.

“You might get one guy who knows that this guy misbehaves quite often so I’ll give him a warning quicker or I’ll be more lenient with a guy because he’s a nice guy and just can’t control himself. I think it really depends on the situation.”

The 20-time grand slam winner believed mistakes were made during the match but hoped it wasn’t due to sexism.

“I hope it’s not the case but I think what happened, obviously there were mistakes along the way and there should be more discretion sometimes,” he said.

“At the same time, they have to do their job, that’s what we want them to do. It’s been tricky but a really interesting case to study.”

Earlier this week Williams broke her silence on the drama, doubling down on her sexism call.

In an interview with The Project, which will air in full on Sunday, Williams remained defiant, reiterating her belief that female players are not treated equally to men.

“I just don’t understand… If you’re a female you should be able to do even half of what a guy can do,” she said.

“I can’t sit here and say I wouldn’t say he’s a thief because I thought he took a game from me.

“But I’ve seen other men call other umpires several things.”

Last week Ramos, the umpire at the centre of the controversy, spoke about the issue to Portuguese paper Tribuna Expresso.

Ramos said he stood by his decisions and believed he treated all players equally.