Neighbours and former classmates are 'shocked' over the news about a Pinner teenager who was collecting a lethal parts of guns in his family home.

Eighteen year old Reza Khalilzada, a former pupil of Nower Hill High School, in George V Avenue, had been stockpiling weapons in his bedroom and had a gun barrel under his mattress for an AK-47 assault weapon he was assembling.

He was jailed on Friday for six years following a trial at Isleworth Crown Court.

Ajanta Ghosh, 35, one of his neighbours in Pembroke Avenue, said: "I am just so shocked, I do not know the neighbours at all, I rarely see them. But hearing that, it's very scary, it's very quiet around here and I have never seen police cars come up here."

Brunel University student Quincy Campbell-Rose, was in Khalilzada's year at his former school. He said: "An old school friend posted the [getwestlondon] article on Twitter and I clicked on it because I saw it had Nower Hill in. I was so surprised. My twin brother couldn't believe it either. He [Khalizada] was quite shy at school and reserved, I didn't hang out with him much, but I would say hello and bye, he had his own group of friends at school. It's just so odd, you think you know someone but actually you do not know them at all."

Dutch-born Khalilzada came to the attention of the authorities when US customs official X-rayed a parcel addressed to him and found it contained a IWI .22 calibre Uzi machine gun and 187 rounds of ammunition rather than the ceramic dish and the owl ornament the label suggested.

US Homeland Security Investigations tipped off the Metropolitan Police and officers from the London force's Central Task Force executed a search warrant at Khalilzada's home - where he lived with his parents and three siblings in a quiet cul-de-sac - on August 14 last year.

Khalilzada told police he had responded to a website advert offering money to provide a 'drop-off address' for an unknown package and was not aware of the contents. But detectives found the barrel of an AK-74 rifle under the mattress in his bedroom and well as a rucksack containing nunchucks, a CS gas cannister, a lock knife, lighter fluid, a catapult and ball bearings, a scarf and bandana, balaclavas, field dressing for wounds, amphetamines, ecstasy, and four CDs containing images and videos of Khalilzada's family.

Detectives seized three computers and a number of USB memory sticks, £600 cash and several bank cards.

Khalilzada was charged with firearms offences on August 15 last year and the next day his parents reported that another American-sourced package had been delivered for him. It contained parts of an assault rifle which, when combined with the rifle barrel found under the mattress, would have created a fully functioning automatic assault rifle with the potential to kill. The ammunition seized at the US border would have fitted this rifle.

Examinations of Khalilzada's computer showed it was heavily encrypted. Khalilzada has refused to supply a password, which he claims he has forgotten.

In 2011 Khalilzada won the 'Most Improved in ICT' award at a spring prize-giving at Nower Hilll High School in George V Avenue, Pinner.

He pleaded guilty on December 3 last year at Isleworth Crown Court to two counts of possession of a prohibited weapon and two counts of possession of a controlled drug, but he denied attempting to possess a prohibited weapon and conspiracy to fraudulently evade a prohibition, for which he was found guilty on Tuesday January 28.