Two local murders have been connected to a man who converted replica sub-machine guns in his shed, before supplying them to gangland criminals.

Grant Wilkinson, 34, who converted the guns into lethal weapons which were used in at least eight murders and 54 shootings, was jailed for life with a minimum term of 11 years at Reading Crown Court on Thursday.

Wilkinson supplied the guns - deadly Mac 10s known as “Spray and Pray” guns capable of firing 32 rounds in under two seconds - from a secret gun factory he ran from two garden sheds.

One of Wilkinson’s guns was used by Jermaine Callum, 18, of Clapham - who gunned down 21-year-old student Robel Tewelde at flats in Stockwell in October of last year.

Another was used in October 2006 by two youths on bikes who shot Antoine Smith near a pizza shop in Clapham. That murder remains unsolved.

Another of Wilkinson’s guns was used to kill WPC Sharon Beshenivsky - who made national headlines when she was killed during a bungled robbery in Bradford in 2005.

As well as those killed 24 people were wounded, and passing sentence judge Zoe Smith said: “The scale of this criminal enterprise is unprecedented in this country.

“The roll call of deaths and injuries is horrific. Some 30 to 40 of these weapons are still unaccounted for, and regrettably but doubtlessly, the roll call of death and serious injury will continue to rise.”

Wilkinson bought 90 replica Mac 10s for £55,000 from a shop claiming he needed them as props for a new James Bond movie.

He converted them at his sheds in Three Mile Cross, near Reading, using a drill and lathe.

He also made bullets out of spent cartridges bought as scrap from firing ranges.

Wilkinson’s secret was only discovered after a curious neighbour peered inside the two 12ft by 12ft sheds and saw bullets and gun barrels.

The guns were sold for up to £2,500 each.

Superintendent Gary Richardson, head of Scotland Yard's Operation Trident murder squad, said the deadly guns were inaccurate: “You can use them close up and they will cause mayhem but they can also hit unintended targets.

“When you go to a Mac 10 shooting and stand where the victim was hit you will find one bullet 25 yards to your left and another 25 yards to the right.”

Police believe Wilkinson's factory was responsible for 90 per cent of Mac 10 shootings since 2004.

Police have found 50 of the Mac 10s and have a £10,000 reward for information about the missing 40.