Secretary Kieran Shanahan said Acting Chief Antonio Asion and Sgt. Benjamin Franklin have been placed on paid leave while the investigation continues.
"I have serious concerns about certain practices involving secondary employment," Shanahan said. "We will conduct a thorough investigation and take action as deemed appropriate. So as not to compromise this ongoing investigation, nor publicly reveal personnel matters, the department will not provide additional details at this time."
Shanahan named Major William Gray of the State Highway Patrol as acting chief while the investigation is ongoing.
The State Capitol Police provide security for public officials, state employees and visitors within the North Carolina State Government Complex and at state-owned properties.