West Midlands Police's former counter terrorism chief has admitted to failing to protect "sensitive documents" after files relating to policing matters were stolen from his car.
Assistant Chief Constable Marcus Beale pleaded guilty to an offence under the Official Secrets Act after the documents were stolen from an unmarked police car in May.
A briefcase containing the papers and other items were stolen from the vehicle after Beale had left them in there for around four or five days.
Beale admitted the offence after being summoned to court following an investigation by Met Police.
Appearing at Westminster Magistrates' Court, the 54-year-old, who is based at West Midland's Police's headquarters in central Birmingham, was fined £3,500. after admitting the charge.
Beale was suspended by West Midlands Police after being charged with the offence.
Following his guilty plea, the force will now consider misconduct proceedings.
Deputy chief constable Louisa Rolfe said: "Today ACC Beale faced grave consequences for a mistake in an otherwise exemplary police career.
"This is a very serious matter and to face criminal charges is devastating for any police officer.
"ACC Beale's distinguished career includes leading the West Midlands Counter Terrorism Unit where he oversaw a number of the UK's most serious terrorism investigations."