Gary Gartner, a longtime political adviser and public affairs representative, said he plans to address questions about the investigation at a Thursday news conference, which he initially had scheduled for this afternoon.
Eight people have resigned from Roberts' office since he took office in January 2013. Ex-scheduler Diane Porter recently filed a claim against the county that contends the supervisor made her work on political activities during work hours and spend office money on campaign materials, and created a hostile work environment, particularly for women.
"A thorough investigation by the District Attorney will confirm that there is no wrongdoing by Dave Roberts," Gartner said in a statement included in an email announcing the one-day postponement of the news conference.
"Supervisor Roberts will ask the county to release to the district attorney the results of the county's confidential internal investigation into these false allegations," Gartner said. "We are confident that the false allegations that have been made by a former employee will be proven to be untrue."
Last week, Roberts' board colleagues said he should bear any liability stemming from the upheaval in his office, not taxpayers. The freshman supervisor represents a North County coastal district formerly held by Pam Slater-Price.