He claims that you’ll only require a £15,000 printer and £100 for everyday materials to create his 3D-printed machine gun.

And pro-gun activist Cody Wilson from Austin, Texas, has been accused of ‘making terrorists’ jobs so much easier’ by handing anyone the chance to build an AR-15 semi-automatic rifle.

The former law student wants to release the digital details for his 3D weapon by April, but he is in a legal fight with the US Government after it told him to take down the code for a pistol he developed.

Shooting practice: A pro-gun activist from Texas has been accused of ‘making terrorists’ jobs so much easier’ by handing anyone the chance to build an AR-15 semi-automatic rifle (pictured being held by a friend)

New technology: 3D modelling involves solid objects to be created from a downloaded online file on a printer

The concept of 3D modelling involves solid objects to be created from a downloaded online file, and Mr Wilson said the materials required to make the gun work are all available at hardware stores.

The 27-year-old told the Daily Mirror: ‘I promise you the reason you haven’t seen this yet is because it has been artificially delayed. I would have demonstrated this for you if I was allowed to.

‘I am fighting my fight with the government but we have a whole new range of things.’ Speaking to reporter Martin Bagot, Mr Wilson confirmed he ‘basically’ had a downloadable 3D machine gun.

The founder of Defense Distributed - who developed the Liberator pistol in 2013 - said the items required to complete the gun include a firing pin in the form of a basic nail.

But his buoyant mood left counter-terrorism expert Hamish de Bretton Gordon fearful that the gun could present a huge risk to Britain, which is under threat from potential attacks by Islamic State.

Former law student: Cody Wilson wants to release the digital details for his 3D weapon by April, although he is in a legal fight with the US Government after it told him to take down the code for a pistol he developed (above)

He told the newspaper: ‘The person who is releasing this is completely irresponsible. We can only hope the authorities in the US are going to deal with this individual. It’s absolutely crazy.’

SHOOT TO KILL: THE AR-15 RIFLE Favoured by target shooters in competitions and by hunters who stalk small game and sometimes deer, the AR-15 is the most popular rifle in America. Police believe that an AR-15 was used by gunman John Zawahri to kill five people in a rampage through Santa Monica before he was himself killed by police in 2013 . It was also the weapon of choice for James Holmes in Aurora, Colorado, and Adam Lanzi in Newtown Connecticut. It fires a 5.56mm, or .223 caliber bullet. Magazines for the weapon (that are in circulation in the US) range from 5 to 100 rounds. With proper training, a shooter can effectively and accurately empty a 30-round magazine in less than a minute. Advertisement

And Andrea Rossel, whose sister Fiona was killed in the 2005 London terror attacks, told the Mirror: ‘There is enough bad stuff on the internet but this is just adding to the threat we face.’

In October 2014 Mr Wilson revealed the Ghost Gunner, an £800 milling machine that can produce metal parts to make untraceable rifles that do not have a serial number.

Rather than creating a gun from scratch, the machine adapts a part known as an '80 per cent lower'. This is the body of the gun that connects its stock, barrel, magazine and other parts.

By milling the part at home, and buying the rest of the parts online, which are not controlled, it is possible to build a semi-automatic weapon with no serial number.

MailOnline revealed in May 2014 how 3D-printing gun enthusiasts were gathering at a website called Fosscad, standing for Free Open Source Software and Computer Aided Designs.

According to one user, for a complete novice who had no knowledge of 3D printers or guns it would take ‘probably a few months to do it well, to print it’ and then build the design into a weapon.

In May 2013 the Mail On Sunday built a 3D weapon from blueprints available on the internet – then smuggled it on to a packed Eurostar train after two reporters passed completely unchallenged through strict airport-style security.

I am fighting my fight with the government but we have a whole new range of things Cody Wilson, Defense Distributed

The pistol, capable of firing a deadly 0.38-calibre bullet, was produced in under 36 hours using a revolutionary £1,700 machine to ‘print’ its components. And because all the parts are plastic, they did not trigger the metal detectors all Eurostar passengers must pass through.

In the past Mr Wilson has argued everyone should have access to guns, saying: ‘I recognise the tool might be used to harm other people… it’s a gun. But I don’t think that’s a reason not to do it.’

In 2014 the UK government 3D-printed at least one gun to try to understand how much of a threat is presented by the technology.

The Home Office says the ‘manufacture, purchase, sale and possession of 3D printed firearms, ammunition of their component parts is fully captured by the provisions in section 57(1) of the Firearms Act 1968’.