Organised criminals are continuing to exploit border weaknesses to smuggle huge amounts of heroin into Bradford from Pakistan and Afghanistan, according to a new report from the Serious Organised Crime Agency (SOCA).

Much of the drug is being sent first to Pakistan then to Bradford through the post, a method revealed by the Telegraph & Argus in March.

The growing use of the post to smuggle drugs is included in the agency's latest report of the threat to Britain from serious organised crime.

The report by SOCA director general Bill Hughes says that drug trafficking poses the single greatest threat to Britain - more than terrorism - with the profits funding more drug deals and other types of crime, and supporting criminal lifestyles.

The worst cities remain London, Birmingham, Manchester and Liverpool, but SOCA said it was becoming more and more concerned with heroin trafficking into Yorkshire.

Mr Hughes said: "Serious organised criminals are adept at exploiting weaknesses in UK border controls to smuggle illicit drugs and people.

"Illicit commodities can be smuggled in the post or through fast parcel services. Large quantities of heroin are sent to the UK from Pakistan and Afghanistan in the post, a large proportion of which is destined for the Midlands and North East, particularly Bradford and Middlesbrough."

At least 90 per cent of Britain's identified heroin supply originates in Afghanistan and about a quarter of the Afghan heroin seized in Britain arrives directly from Pakistan by air, according to SOCA.

Postal packages are commonly sent to rented houses where they are picked up, cut and bulked out with other substances.

In March, Chief Superintendent Allan Doherty, divisional commander for Airedale and North Bradford Police, said the packages were arriving in Bradford "on a regular basis".

Chief Supt Doherty, who heads the Crackdown in Bradford, A Community Against Drugs' initiative, said: "Some are detected en route and seized or we might let it go on and track it."

Heroin wraps are now sold for about £10 in the city but cut-price dealers are offering discounts on double deals of crack cocaine and heroin, known as white and brown.

Detective Inspector Neil Benstead, head of the Bradford District Drugs Team, said: "These dealers treat it as a business and they will offer discount to increase their business."

Following the publication of the SOCA report, Shipley Tory MP Philip Davies called for Royal Mail and other parcel companies to "co-operate fully" with its offices to address what has become a "massive concern" .

He said: "The only hope is that SOCA can work with some of the parcel companies and the Royal Mail to ensure there is better screening of the parcels for drugs."

e-mail: marc.meneaud @telegraphandargus.co.uk