A South Texas sheriff's deputy has been charged with raping a female inmate in a transport van in the jail parking lot.

Erick Montez was being held Wednesday in San Antonio on felony charges of sexual assault and violating the civil rights of a person in custody.

The Bexar County Sheriff's Office on Tuesday announced the arrest of the 35-year-old detention officer and plans to fire him.

The inmate reported that Montez forced her to have sex with him Dec. 27 in the van while he was on duty. A sheriff's statement says surveillance video appears to support the allegations. Investigators did not release further details on the woman.

KSAT.com, citing the criminal complaint, reported that the alleged victim was transported “during the midnight hours” by Montez and that there is no reason for the transport to occur. The complaint reportedly said Montez admitted to having sex with the alleged victim.

Jail records don't list an attorney to speak for Montez, whose bond was $85,000. He's been a deputy since 2008.

The Associated Press contributed to this report