A San Francisco sheriff’s deputy assigned to the county jail was charged with battery on Monday for allegedly assaulting an inmate, according to the district attorney’s office.

Nanette Musto was accused of touching a female inmate’s chest on Sunday without her consent at San Francisco Jail Number 2, located on Seventh Street.

The jail and sheriff’s office are already under scrutiny after two federal lawsuits were filed by different groups of inmates alleging abuse by staff and unconstitutional conditions at the jail.

The misdemeanor complaint filed Monday accused Musto of asking the woman whether she had had breast augmentation, based on rumors she had allegedly heard from other inmates, before reaching out and grabbing the woman’s breast, according to the DA’s office.

The 51-year-old deputy was charged with battery and assault by a public officer.

The DA’s office said in a statement that surveillance footage supported the woman’s accusations and that the alleged victim felt “humiliated and embarrassed.”

Tara Moriarty, a spokesperson for the sheriff’s office, said the office took such complaints “very seriously” and conducted its own internal investigation.

“Upon completion of that investigation, the case was referred to the San Francisco District Attorney’s Office for independent review and charging consideration,” Moriarty wrote in an email.

Musto was reassigned while the criminal case proceeds, Moriarty said.

Danilo Quintanilla, a spokesperson for the San Francisco Deputy Sheriff’s Association, the union representing sheriff’s deputies, said the union would provide Musto’s legal representation as a standard practice for its members.

“These are allegations, and like every person charged with a crime, our member is entitled to the presumption of innocence and due process under the law,” Quintanilla wrote in a text message. “The criminal justice system exists to prove facts, and it would be inappropriate for the SFDSA to comment on the evidence or merits of a pending case.”

Musto is scheduled to be arraigned Tuesday at 9 a.m. in San Francisco Superior Court at 850 Bryant St.

The San Francisco Sheriff’s Office is already facing a separate federal class action civil lawsuit filed in May by 20 other female inmates who said they were recorded with body worn cameras and humiliated during a mass strip search.

Another federal civil complaint filed in June alleged that conditions at the jail are unconstitutional because of lack of sunlight and other deprivations and practices.