A Customs and Border Protection officer has been arrested on charges of conspiring to smuggle drugs and illegal immigrants.

The FBI said Luis Francisco Alarid was arrested Friday night and is due to make an initial appearance Monday before a federal magistrate judge. He is being held at a San Diego jail.

CBP spokesman Vince Bond said Saturday that the 31-year-old officer has been placed on paid leave. He has worked at San Diego's Otay Mesa border crossing, which borders Tijuana, Mexico.

The FBI and CBP declined to elaborate on the case. No one answered the phone at a San Diego-area listing for a Luis Alarid.

The case will be prosecuted by the U.S. attorney's office in San Diego