There may be another ethical breach in Judge Luis Gonzalez’s court.

The presiding justice of the Appellate Division’s First Department, already under investigation by a state oversight panel, has employed an executive assistant who may be doing double duty.

Gonzalez hired Susan Hernandez-Roura in May 2010 as a lawyer earning $99,599, later promoting her to his top assistant at a salary of $126,000.

Hernandez-Roura practiced law downtown before joining the court, and a Post reporter who recently called the firm was told she was available for a consultation.

State rules say a lawyer employed full-time by the court system cannot, with few exceptions, practice law.

The Post has revealed that Gonzalez claimed a Brooklyn home as a primary residence on mortgage documents, while insisting he lived in the Bronx.