Police announced Tuesday afternoon that an investigation is underway.
The victim told police that she was sexually assaulted by a male teacher at an off-campus location during the 1976-77 school year.
"Subsequent investigation revealed that this teacher is still employed by the school," said a department news release.
Eyewitness News called Garces High for a response. School president John Fanucchi said he cannot comment but referred inquiries to the Office of Catholic Education.
Superintendent of Catholic Schools Richard E. Sexton responded with a written statement. He said the Diocese of Fresno received information that an employee of Garces Memorial may have committed a criminal act with a student in 1976. An internal investigation was opened, and the matter referred to Bakersfield police.
The employee has been placed on administrative leave off campus while the matter is investigated.
"We are unable to provide further details or other information at this time, as the matter is under investigation and to protect the good name of all parties," the superintendent's statement read.