South Yorkshire Police’s Sergeant Paul Duke was off-duty when he committed the offence on March 3.
The 45-year-old was given a 12-month conditional discharge and ordered to pay £620 costs and £16.99 compensation after being found guilty following a trial at Doncaster Magistrates Court this week.
Duke was reported for summons following a complaint from a member of the public.
The case was initially referred to the Independent Police Complaints Commission, then returned to SYP for a local misconduct investigation, which will be carried out by the force’s professional standards department now that criminal proceedings have concluded.
Detective Supt Terry Mann, head of the department, said: “Members of the public quite rightly expect higher standards and behaviour from our officers and staff and anyone who is found to have fallen short of those standards by committing a crime will be thoroughly investigated and put before the courts.
“The force expects its staff to act with integrity and professionalism to ensure people receive a high quality service and have a police service they can be proud of.”
Duke was previously based in the custody suite in Barnsley. It is currently being considered whether he will work for the force while the internal misconduct investigation is carried out.