The International Tennis Federation has backed umpire Carlos Ramos in the row over his handling of the US Open final, saying he acted with “professionalism and integrity”.

The experienced Portuguese official has found himself at the centre of a storm involving accusations of sexism and racism over the way he treated Serena Williams.

Williams was docked a game in the crucial second set of her match against Naomi Osaka for calling the experienced Ramos a “thief” having previously received two code violations – and she used her subsequent post-match press conference to call her penalty “sexist”.

Her stance was swiftly backed by the WTA Tour’s chief executive Steve Simon and US great Billie Jean King, both of whom also questioned the initial code violation handed to Williams for on-court coaching.

Having initially said it would not comment, the ITF, the world governing body, later released a statement in support of Ramos’ decision-making.

The statement read: “Carlos Ramos is one of the most experienced and respected umpires in tennis.

"Mr Ramos’ decisions were in accordance with the relevant rules and were re-affirmed by the US Open’s decision to fine Serena Williams for the three offences.

“It is understandable that this high profile and regrettable incident should provoke debate. At the same time, it is important to remember that Mr Ramos undertook his duties as an official according to the relevant rule book and acted at all times with professionalism and integrity.”

Former umpire Richard Ings, who penalised John McEnroe a game during a match against Boris Becker in 1987, hailed Ramos for his decisions and said he umpired the match “absolutely perfectly”.

Speaking on BBC Radio Four’s Today programme, Ings said: “Carlos Ramos is an umpire with 40 years of experience.

“He handled that match absolutely perfectly. He saw violations and he had the courage of his convictions to call them when he saw them.

“I support him 110 per cent. It was one of the best officiating jobs that I’ve seen in years.”

Osaka, for whom this was a first Grand Slam title, had to be comforted by Williams on the podium as loud jeers erupted around the stadium.

Talking to the Today show on NBC, the 20-year-old said: “I felt a little bit sad because I wasn’t really sure if they were booing at me, or if it wasn’t the outcome that they wanted.”

Osaka blocked out what was going on around her as she tried to focus on winning the match, and has not yet had a chance to watch the footage back.

She said: “I can’t really form an opinion right now. For sure I want to watch everything and I want to know what happened because this was one of the biggest things that happened to me.”