A police sergeant allegedly took a second job despite being denied permission by Avon and Somerset Constabulary.
Sgt Christopher Tearle, based in Radstock, faces a misconduct hearing at the force headquarters in Portishead on Friday, February 21.
A publicity notice on the police website said the officer was accused of breaching the standards of professional behaviour in terms of honesty and integrity; orders and instructions; and discreditable conduct.
It said: “The alleged facts are: PS Christopher Tearle undertook paid work for a business interest (engineering role) despite knowing the request had been declined and while suspended from duty.
“It is contended that (if proven) the allegations amount to gross misconduct.”
The hearing is expected to last one day.