A senior counter-terrorism police officer who had top-secret documents stolen from his car has been dismissed without notice for gross misconduct.

After a special case hearing on Wednesday, the chief constable of West Midlands police, Dave Thompson, ordered that Asst Ch Con Marcus Beale be dismissed after a briefcase of papers disappeared from the boot of his vehicle.

“The conduct in this case is a serious criminal conviction for improperly caring for documents,” Thompson said. “I agree (with a previous disciplinary panel decision) that the misconduct in this case is serious and is very likely to undermine public confidence in policing.”

Beale, 54, who was due to retire next week, pleaded guilty last year to an offence under the Official Secrets Act and was fined £3,500. He argued that he should not be dismissed and should only receive a final written warning.

Addressing the hearing at the West Midlands police headquarters in Birmingham, Beale’s counsel, John Beggs QC, said a dismissal would be “merely symbolic” in light of the officer’s imminent retirement. Beale will retain a £215,000 tax-free pension lump sum.

Beggs argued that Beale had reported the documents as missing immediately and his failing had been unintentional with no malice or premeditation.

“Mr Beale’s response to this ghastly realisation (that documents had been stolen) was swift, professional, selfless, and imbued with the characteristic that runs through him like Brighton rock – honesty and integrity,” he said.

In February, a disciplinary panel recommended that Beale be dismissed by the force, but the final decision was left to the West Midlands police chief constable.

The disciplinary panel heard how Beale left the documents in the car boot for five days, during which he went to the pub, spent a weekend away in London with his wife, and went supermarket shopping. The documents were never supposed to leave police premises.

The case contained four documents, which included minutes from a high-level counter-terrorism meeting, counter-terrorism local profiles, details of regular organised crime and sensitive information about a high-profile investigation. Beale only discovered that the briefcase was missing when he stopped at Warwick services on 15 May 2017 while on the way to Oxford.

During the previous hearing, Fiona Barton QC, representing the force, said there was no sign of a forced entry to the car and that it was “an extraordinary mystery” how the documents had been stolen.

She said the impact of the incident could have been catastrophic and it was “a matter of luck the documents do not appear to have seen the light of day”.

• This article was amended on 19 April 2018. An earlier version incorrectly said that Beale would lose a £215,000 tax-free pension lump sum when in fact he will retain it.

