An investigation was begun this week into a threatening phone call made to the Los Angeles County Counsel during which the caller identified himself as a sheriff’s sergeant and demanded that the attorney go to sheriff’s station to surrender for failing to appear following a2006 grand jury summons.

The call—which comes as the Board of Supervisors spars with Sheriff Alex Villanueva over the reinstatement of a fired deputy and other matters—was made April 20 to the personal cellphone of County Counsel Mary C. Wickham, according to the county’s interim Inspector General Rodrigo A. Castro, whose office is conducting the investigation.

The caller threatened to come to Wickham’s home and arrest her after Wickham said there was no basis for the demand, according to Castro’s office.

The Los Angeles County Sheriff’s Department assigned the case to its Major Crimes Bureau, which stands ready to “launch a full assessment of this potential threat,” according to Lt. AJ Rotella of the Sheriff’s Information Bureau.

Residents have reported receiving similar calls from people claiming to be sheriff’s officials, according to Rotella.

The callers in those cases have claimed the call recipient had failed to appear for jury duty or grand jury duty, according to the sheriff’s department.

“With some of these calls, the suspects have been able to mask their telephone numbers to appear as if they are calling from within the Sheriff’s Department, in an attempt to appear to be legitimate,” according to Rotella. “At this time, multiple criminal reports have been taken at various stations and are in the early investigative stages.”

County Supervisor Hilda Solis issued a statement saying the call to Wickham was aimed at deterring her from doing her job.

“Threatening a public servant is despicable and will never be tolerated,” Solis said. “This undemocratic intimidation is designed to chill the County Counsel from doing her job.”