NEW BERLIN, Wis. (CBS 58) -- The City of New Berlin police conducted a traffic stop on Saturday, Dec. 2. 

According to the Waukesha County Sheriff's Department, the driver and the sole occupant of the vehicle was a 28-year-old male. He was arrested during the traffic stop and transported to a local hospital to continue the investigation. 

 A City of Oconomowoc police officer was assisting the New Berlin officers with their investigation, said the sheriff's office. 

According to the sheriff's office, based off of initial information gathered, the man was cooperative throughout. 

While at the hospital, the 28-year-old became unresponsive and medical staff immediately provided him care. He was pronounced dead shortly after. 

By policy, New Berlin Police have placed three officers on administrative leave pending the outcome of the investigation. The investigation is ongoing, according to authorities.