Rabbi Henry Sobel, a Brazilian human rights activist who led Latin America’s largest liberal Jewish congregation and who drew wide attention for defying his country’s dictatorship in the aftermath of a notorious political killing, died on Friday in Miami. He was 75.

The cause was complications of lung cancer, relatives said. He had lived in Miami since 2013.

Rabbi Sobel (pronounced so-BELL), a Lisbon native who led the Congregação Israelita Paulista in São Paulo , was a national figure in his adopted homeland, his counsel sought by presidents, popes and the Dalai Lama.

He came to prominence in Brazil in 1975, after Vladimir Herzog , the news director of a São Paulo television station, was murdered in prison by his military torturers a few hours after he was arrested, accused of being part of a Communist network. The murder shocked Brazilians and was denounced by Archbishop Paulo Evaristo Arns of São Paulo, another champion of human rights.

The dictatorship falsely claimed that Mr. Herzog had committed suicide; it made public a photograph, later proved to have been staged, that purported to show Mr. Herzog hanging from a belt in his cell. Suicide would have relegated his burial to a remote corner of the Cemitério Israelita do Butantã. (Historically, Judaism has regarded suicide as defying God’s will.) But Rabbi Sobel chose to inter Mr. Herzog at the center of the cemetery, with full rites.