A leading police group says sales of an airgun, which can be illegally adapted to fire live bullets, must be banned.

The Association of Chief Police Officers (ACPO) wants a national ban on the public sale of the Brocock air cartridge pistol because of the risk posed by the weapons.

ACPO firearms adviser David McCrone, who is Deputy Chief Constable of Greater Manchester Police, told BBC's Newsnight programme: "There is evidence which would justify banning them."

Mr McCrone said new legislation is required to give the Home Secretary the power to ban weapons like the Brocock air cartridge pistol when they become a threat to public safety.

Police want a ban on the public sale of the airguns

The pistols are imported and distributed by the Birmingham-based company Brocock, which makes the air cartridge system that powers the air gun pellets.

Brocock said in a statement: "Both the police and a Home Office ballistics expert confirm that we're already doing everything possible to prevent the illegal conversion of these products which are sold through a network of registered dealers."

Alan Shiers, an officer with the National Criminal Intelligence Service (NCIS), has been collating information from police forces across the country

He told BBC's Newsnight that conversion of Brococks amounted to a "major problem" which had to be tackled.

Special sleeves

He said: "We're having reports of this type of weapon being recovered not just in London where the problem started - but it's now spread to Manchester, Nottingham, Bristol, all over the country."

Figures from NCIS show that converted Brococks now account for 35% of all guns recovered by the police.

When used legally, the airgun fires small pellets using a compressed air charge in a cartridge that is loaded into the pistol.

Brocock air cartridge pistols are purchased by our customers for the legal pursuit of their sport

Brocock, pistol importer

But criminal gangs have been adapting the guns by fitting special steel sleeves inside the chamber of the gun, enabling live .22 calibre bullets to be fired.

In October, Bradford taxi driver Mohammed Basharat was murdered with a converted Brocock pistol.

This weapon had been drilled out to take more powerful .38 calibre bullets.

In their statement, Brocock also said : "We are advised by the police that some illegally converted weapons have been recovered.

"We accept there may be a rare occurrence of illegal conversion and are co-operating with the police in every way.

"Brocock air cartridge pistols are purchased by our customers for the legal pursuit of their sport.

"We have not considered removing a legitimate and tightly regulated product from the market."