The Catholic Church’s former top official in New York, Cardinal John Joseph O’Connor, was the son of a rabbi’s daughter, the New York Times reported Tuesday.

O’Connor’s sister, 87-year-old Mary O’Connor Ward-Donegan, told the paper that investigation of her mother’s family tree found that her maternal grandmother was Tina Ruben, wife of Rabbi Gustave Gumpel, who was buried in a Jewish cemetery in Fairfield, Connecticut.

Tina and Gustave’s daughter, identified as Deborah on her 1887 birth record, Dora in 1900 census records, and Dorothy Gomple after converting to Catholicism in 1908, lost her mother as a toddler and left the family once she was of age.

It’s not known whether Dorothy ever disclosed her origins to O’Connor, who died in 2000.

O’Connor was a close friend of Jewish New York mayor Ed Koch and helped push the Vatican to recognize the state of Israel in 1993.