BBC's China editor has resigned from her post in protest at being paid less than men working for the corporation in similar positions, accusing the corporation of a "secretive and illegal" pay culture.

Carrie Gracie, who became the BBC's most senior representative in China four years ago, stepped down after learning that her male counterparts were paid significantly more than she was.

Gracie, who acted as guest presenter of the BBC Radio 4 Today program in December and again this month, will return to her former post in the TV newsroom.

In an open letter to BBC license fee payers, she said: "It is pay discrimination and it is illegal". She urged the BBC to admit the problem and set in place an equal, fair, and transparent pay structure.

Gracie is fluent in Mandarin and has worked on Chinese issues for almost 30 years. She took the job as China editor when it was newly created, on the urging of the corporation.

During the past four years, the BBC has had four international editors – two men and two women. Gracie said the Equality Act 2010 states that men and women doing equal work must receive equal pay. However, she learned in July that the two men earned at least 50 percent more than the two women during the previous financial year.

Gracie had refused a 45,000 pound pay rise because she believes it still left a "big gap" between what she was earning and her male peers. She said all she wanted was to be "made equal".

Peter Oborne, a British journalist tweeted that Gracie was paid 135,000 pounds while Jon Sopel, the BBC's US editor, was paid between 200,000 and 250,000 pounds.

Gracie said: "The rise of China is one of the biggest stories of our time and one of the hardest to tell. I cannot do it justice while battling my bosses and a byzantine complaints process."

Broadcasters across the country voiced their support for Gracie on Twitter, using the hashtag #istandwithcarrie.

David Schlesinger?, former chairman of Thomson Reuters China, said: "An extraordinary act of courage and principle by one of the best ever China reporters, Carrie Gracie."

Iain Dale, a presenter for London radio station LBC, said: "I've read Carrie's letter and I don't see how anyone can disagree with a word of it. There are four BBC international editors and she is paid far less than the other three for doing an infinitely more difficult job. An utter disgrace. Credit to her for making a stand."

In response to Gracie's resignation, a BBC spokesperson said: "Fairness in pay is vital. A significant number of organizations have now published their gender pay figures showing that we are performing considerably better than many and are well below the national average. Alongside that, we have already conducted an independent judge-led audit of pay for rank and file staff which showed 'no systemic discrimination against women."

The BBC has pledged to close the gender pay gap by 2020.

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