A Bradford man was the lynchpin in a vast gun-running conspiracy which saw "assassin's kits" sold on the city's streets.

Madasser Ali, 30, of Great Horton Road, Bradford, masterminded a gang that conspired to buy dozens of guns and sell them throughout the north of England.

Ali, who will be sentenced next month, and six other defendants had earlier pleaded guilty to their parts in the conspiracy, but details of their involvement were only released yesterday when Kaleem Akhtar, 29, of Chorlton, Manchester was found guilty of conspiracy to possess firearms and ammunition with intent to endanger life after an eight-day trial at Manchester Crown Court.

The operation has been linked to the sale of at least 56 guns worth around £1,500 each, and nearly 900 bullets.

Ali pleaded guilty to conspiracy to possessing firearms and ammunition with intent to endanger life.

Codenamed Operation Tumbler, Manchester police's Armed Crime Unit launched the investigation after information was received about Russian-made Baikal handguns being sold in Manchester. The court heard earlier this month that the guns, brought from Essex, were found in Bradford, Leeds, Manchester, Liverpool, Sheffield and Scotland.

The guns had been expertly converted to fire live rounds of 9mm ammunition, and had all been marked with Roman numerals so that each part of the gun could be carefully matched, maximising quality.

After conducting surveillance operations, officers arrested Michael Peake on the M602 in February 2007 when he tried to leave Manchester having picked up some of the kits.

Two guns, two silencers and 30 bullets were found in the boot of his car.

Over the next nine months the Operation Tumbler team seized 29 Baikals and all the bullets in the form of assassin's kits. They were seized before they could hit the streets and be used in crime.

Additionally, 27 of these distinctive guns that had been packaged and shipped as far as Glasgow and South Yorkshire have been linked to this conspiracy.

Detective Inspector Chris Packer from GMP's Armed Crime Unit, who led this investigation, said: "Led by Madasser Ali, Kaleem Akhtar and his stooges were driven by greed and criminal status, and did not care about what these guns can do to people.

"Akhtar's arrogance throughout this investigation has been astonishing. Along with Ali he even continued arranging for guns to be packaged and sold after he knew that we had seized some of the guns and arrested some of his cohorts. I am really pleased with today's result.

"Of these high quality and very dangerous guns we have recovered it is a miracle that none were used to kill someone. Each one of those 856 bullets could have been somebody's life.

"Since the conspirators were arrested late last year only two more of these distinctive Baikal revolvers have been recovered by police. Clearly these men were key to the regular distribution of these guns and it is possible that they are responsible for many more guns getting into the hands of people who would use them in the worst possible way.

"The removal of these men from the streets, not to mention all the guns and ammunition, is a brilliant result, and one that without a doubt has made us all safer.

"The seizure of 13 guns at one time is the second single biggest seizure of weapons to be made in GMP's history. It marks the culmination of 18 months dedicated work by a team of my officers, and it makes me proud to think of the lives that have been saved by this operation."

Paul Wilson, 36, of Liverpool Road in Southport also pleaded guilty to the conspiracy charge.

Asaid Saleem, 27, of Bedford Road, Trafford was employed by Akhtar to package the guns into the assassin's kits, and transport them to suppliers.

He pleaded guilty last year to possessing firearms and ammunition with intent to endanger life, possessing prohibited weapons and ammunition and possessing ammunition without a firearm certificate. He also pleaded guilty to the conspiracy charge on 10 April this year.

Lithuanian brothers Agnius and Edgaras Malcevas, 26 and 39, respectively, who both live in Essex, were responsible for driving the guns up to Manchester to meet with Madasser Ali.

Agnius pleaded guilty to the conspiracy charge, and possession of a firearm with intent to endanger life. Edgaras pleaded to the lesser charge of possession of a prohibited weapon.

The final member of the conspiracy was the first to be arrested. Michael Peake, 44, of Lancing Drive, Liverpool, pleaded guilty last year to possession of firearms with intent to endanger life, and possession of a prohibited weapon.

A date for sentencing of all seven defendants will be set on 2 June 2008.