A Dunkin’ Donuts worker has been arrested after an Illinois State Police officer discovered a “large, thick piece of mucus which was later confirmed to be saliva” in his coffee, authorities said.

The incident took place at 10:20 p.m. on July 30 when an Illinois State Police (ISP) District Chicago trooper purchased a large black coffee from Dunkin’ Donuts on Archer Avenue in Chicago, ABC News reported.

“Due to the coffee being extremely hot, the Trooper removed the lid from the top of the cup to cool it down,” the Illinois State Police said in a statement.

It was at that moment when the officer discovered the saliva floating in his cup.

The ISP immediately opened an investigation into the incident, which concluded with the arrest of Vincent J. Sessler, a 25-year-old Dunkin’ Donuts employee.

“This is outrageous and disgusting,” said ISP Director Brendan F. Kelly. “The men and women of the Illinois State Police put their heart and soul into protecting the lives and rights of all people in this state every day. They deserve better than this insulting and dangerous treatment.”

Kelly said that he and other ISP officers would be banned from patronizing that location for their own safety.

Sessler is currently in custody at Chicago Police Department’s Eighth District while the police continue their investigation.

Sadly this is not the only time an officer has been mistreated at a dining establishment for being a police officer. One New Jersey restaurant employee wrote “cops pigs” on an officer’s receipt. The employee was promptly fired.