SÃO PAULO, Brazil — Thousands of Brazilians and foreigners have flocked to the small town of Abadiânia in central Brazil for years, lured by tales of a miraculous healer known as John of God who slices into patients without anesthesia and claims to channel spirits of the dead to cure conditions like cancer and chronic depression.

In recent days, dozens of women have come forward to accuse the famous medium, whose real name is João Teixeira de Faria, of being a serial sexual abuser who preyed on vulnerable patients during would-be healing sessions.

Their accounts have upended the image of Mr. Faria, whose global fame exploded after Oprah Winfrey broadcast a profile of him in 2010 and then interviewed him during a visit to his center in 2012.

As prosecutors sift through a mounting pile of victim statements, Mr. Faria appears likely to become the first major Brazilian casualty of the #MeToo movement, which so far has reverberated relatively little in Latin America’s largest nation.