Mexico union leader Elba Esther Gordillo in court
Union head Elba Esther Gordillo, considered Mexico's most powerful woman, has been charged with the use of illicit funds and conspiracy.
Ms Gordillo, who runs the 1.5 million-member Mexican teachers' union, was arrested on Tuesday and is alleged to have embezzled more than $200m.
She reportedly spent millions on a US department store, plastic surgery, property and a private plane.
Her arrest came a day after the enactment of major educational reforms.
Will Grant reports from Mexico City.