Chattanooga City Councilman Larry Grohn, who is running for mayor opposite incumbent Andy Berke, has accused Berke of using WhatsApp to deliberately evade records rules.
The mayor has admitted to using WhatsApp to conduct city business, and Grohn in a news release charged that "this was a deliberate attempt to evade the [Freedom of Information Act] laws and keep these communications from taxpayers."
The app allows message senders and recipients to store messages and phone calls. But, unlike an email sent using the city's email server, Whatsapp does not store messages sent by its users.
"The mayor and any of his staff, in the spirit of transparency, could have saved the messages in order to comply with the law," Grohn said.
City spokeswoman Marissa Bell said, "City of Chattanooga employees have the right to use any app they choose on their personal phones, including common messenger apps like the popular What's App which is owned by Facebook and used by over a billion people worldwide."
Berke, in response to calls by the Hamilton County Republican Party to resign as mayor because of his use of encrypted communications to conduct city business, called such allegations a "blatantly partisan attack."
He said public officials are expected to communicate through many mediums, including social media and text messages, and said that the mayor's office complies fully with open records laws.
"As to my understanding, most cities have no policy about text message and electronic communication," Berke said. "We've put forth a policy that says exactly what [city employees] have to do. So in most places, you could delete the next day. We don't do that. We try to go above and beyond by putting forth a policy that says what we need to do."
City officials have stressed that a record and information policy adopted in December 2015 requires chat messages be retained for at least 60 days and emails for five years. In an emailed statement sent last week, Berke said his office had fulfilled 3,314 open records requests so far this year.
Concerns over text communications by Berke and his senior staff arose after a domestic incident involving adviser Lacie Stone and her husband, Bobby. Bobby Stone alleged his wife was having an affair with Berke, who has denied the claim.
Bobby Stone was charged with assault and vandalism, but his court case has been repeatedly delayed while awaiting results of a Tennessee Bureau of Investigation probe into the allegations.
Berke is completing his first term as mayor and has said he will seek re-election in March 2017.