The UK Government's most senior adviser on Scots law has been fined £1000 after admitting a firearms offence.

Advocate General for Scotland Richard Keen QC pleaded guilty to breaching section two of the Firearms Act 1968 by failing to secure a shotgun at his home in Edinburgh's New Town.

Lord Keen, a former chairman of the Scottish Conservative Party who was made a life peer in 2015, did not appear when the case called at Edinburgh Sheriff Court on Wednesday but he pleaded guilty by letter.

Sheriff Frank Crowe said: "I do take into account Mr Keen's previous good record and the fact that he admitted his guilt at the outset.

"Nevertheless to hold a firearms certificate is a privilege and there are very strict conditions which have to be adhered to to prevent such weapons falling into the wrong hands.

"There was a potential risk with the shotgun not in the secure cabinet as laid down by the regulations."

The court heard the offence came to light when police were called to a break-in at Lord Keen's home on Ann Street, Edinburgh, on Hogmanay last year when he and his wife were away on holiday.

Officers searching the property found the 12-bore Stephen Grant shotgun in a basement out of its secure cabinet.

Solicitor advocate Simon Catto, representing Lord Keen, said he had been out shooting on December 27 and on returning home had taken the gun to the basement intending to clean it but had then "forgotten about it through his own carelessness" before departing for holiday the following day.

Mr Catto said Lord Keen had contacted police himself on Hogmanay after receiving a mobile phone alert that his alarm system had been triggered.

While the upper floors of the property had been ransacked, the burglars had not entered the basement, he said.

Mr Catto said: "He's a keen shot, he shoots approximately 10 times per year. He has been a shotgun enthusiast for around 25 years and has held a firearms certificate.

"He is therefore fully aware of what's expected and required of him in terms of the certificate. He accepts on this occasion he fell below that."

Mr Catto added: "The house was locked, the alarm was set and no one else had authority to enter the property.

"Other than the burglars who had no business being there, no one else would have access to the property.

"This case and the consequent publicity has been the source of considerable embarrassment and he has pleaded guilty at the earliest opportunity."

The sheriff said: "It is very fortunate that when the house was ransacked that the housebreakers did not go down to the basement area."

Lord Keen, 62, was given 14 days to pay his fine.

One of Scotland's leading lawyers, he is a former dean of the Faculty of Advocates and was appointed advocate general in May 2015.

He recently represented the UK Government at the Supreme Court hearing on the triggering of Article 50, arguing the consent of the Scottish Parliament was not needed before negotiations on Brexit formally begin.

Among his most high-profile cases was the successful defence of Al Amin Khalifa Fhimah at the Lockerbie bombing trial, at which his client was acquitted of all charges.