A Bexar County Sheriff's Department deputy was arrested on a felony charge of super aggravated sexual assault Sunday after a 4-year-old girl's mother was blackmailed to stay silent about the abuse, according to police. The victim's mother is an undocumented immigrant and was threatened with deportation if she spoke out.

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KENS reported that department officials arrested detention Deputy Jose Nunez, 47, after the victim told her mother about the abuse Saturday night in San Antonio, Texas.

Sheriff Javier Salazar said at a news conference Sunday that the mother went to a local fire station and Nunez was arrested.

"The details of the case are quite frankly heartbreaking, disturbing, disgusting and infuriating all at the same time," Salazar said, adding that Nunez had physical contact with the victim and there was "at least some indication of minor injury."

"We have reason to believe that this goes back at least several months, possibly a couple of  several years," Salazar said.

Nunez, a 10-year veteran of the department, is on administrative leave pending an investigation.