The death of a 2-week-old baby boy who contracted herpes following an ultra-Orthodox circumcision is being investigated by the Brooklyn District Attorney’s Office.

A spokesman for DA Charles Hynes yesterday confirmed that prosecutors are looking into the Sept. 28, 2011, death at Maimonides Hospital.

The infant had been circumcised in a controversial religious ceremony in which a rabbi or mohel draws blood away from the freshly circumcised penis with his mouth.

In 2004, another baby died after catching herpes from a Rockland rabbi who performed the bris.