Two Dunedin police officers required medical treatment after being spat at by a Hepatitis C positive offender.
The 35-year-old woman, who is known to police, was being processed at the Dunedin Central police station yesterday for an unrelated incident of wilful damage.
While being processed she spat at two officers, who were taken to a medical centre for treatment and testing.
Acting Senior Sergeant Trevor Thomson said officers had the option to use a spit guard while handling offenders, however, the woman's actions were out of the blue.
"When you are dealing with police and it's amicable you wouldn't [use a spit guard]," he said.
"It was out of the blue, this situation."
The officers had now returned to duty, Mr Thomson said.
The woman was charged with assaulting police and wilful damage, and will appear in the Dunedin District Court.