An investigation has begun into alleged misuse of the North Wales Police computer system.
The Independent Police Complaints Commission (IPCC) said a police officer had been arrested and suspended while the inquiry is carried out.
The IPCC said its investigation would also look into the subsequent release of information.
IPCC commissioner Tom Davies said the allegations against the officer were "very serious".
The inquiry will be managed by an IPCC investigator.
The IPCC said that because of the potential for legal proceedings, it would not release any further information about the case at this time.