Derrick Bird held a firearms licence for 15 years before he embarked on his killing spree.

The taxi driver, who was convicted of theft in the 1990s, acquired the licence in 1995 and had also held a firearms licence for a .22 rifle since 2007.

Police have confirmed that these licences covered the two weapons recovered yesterday.

He is understood to have been a licensed firearms holder since the age of 32.

Under British law, those wishing to acquire a gun must complete applications and interviews with the police or firearms licensing authority before they acquire a weapon.

The country’s firearms licensing system is among the toughest in the world and licence holders have to provide reports from their doctor, disclose any criminal convictions and state why they want a gun.

It takes eight weeks on average to complete the process.

But despite the length of the procedure, nearly 600,000 people in the UK legally own a shotgun and just over 100,000 own a firearm.

A shotgun is defined by its smooth bore and fires cartridges or blanks, while a firearm has a rifled barrel and fires bullets.

Firearms expert Michael Yardley, spokesman for the Shooting Sports Trust, described the process of acquiring a shotgun or firearm as “complicated”.

He said: “You have to apply to the police by filling out a form. You have to declare criminal convictions.

”You have to provide details of your GP and his or her address and police will follow that up.

”The police will come and see your security measures - for example, that you have a gun cabinet.”

Mr Yardley, who gave evidence to the inquiry into the Dunblane school shootings in 1996, added: “The majority of legal gun owners are responsible and use their weapon for sport and hunting.”

The Cumbria shootings, he suggested, had all the hallmarks of so-called “amok killings” - when the killer has snapped and embarked on a random spree.

Gun enthusiasts expressed dismay and shock at the killings, but were quick to defend the UK’s licensing laws.

British Association for Shooting and Conservation (BASC) spokesman Simon Clarke said: “The events in Cumbria are tragic and shocking and as representatives of Britain’s lawful gun owners, BASC would like to make clear its deeply-felt sorrow at these events, which will have long-lasting repercussions within the affected families and communities.

”Britain’s firearms licensing system is amongst the toughest in the world and includes numerous safety and medical checks and balances.

”The UK has a well-worked approach to draw all possible lessons from any such event and we will co-operate fully where our expertise is appropriate.”