According to a news release, the incident occurred at offices formerly occupied by Garner EMS at 920 Seventh Avenue on September 1.
The news release did not name the employees or give further details.
"The crime, we're classifying it as a sexual assault, and that's all the details we're going to release," explained Garner Police Lieutenant Chris Hagwood.
Just one day before police announced their investigation publicly, EMS chief Bill Frederick resigned. He had worked for the organization for 12 years.
Police will not say if he's their suspect or if his resignation has anything to do with the alleged assault.
Garner Mayor Ronnie Williams told ABC11 he doesn't know if the reported assault occurred while the two EMS employees were on duty. He wants answers and said he's glad police are taking it seriously.
"This was more than hankie pinkie. It's serious business and why police are involved with a thorough investigation," said Williams.
Garner Police say the public will get answers.
"I ask that everyone involved in this allow us the time to do our investigation," said Hagwood.