British and Jamaican police collaborated for several years to bust a money-laundering scam being run by a Jamaican drugs gang, which was sentenced on Thursday.

According to a report by BBC News, the investigation was sparked by a routine raid on a drab terraced home on Dundas Road, Tinsley, in Sheffield, in August 2003. The investigation ended with the conviction of key members of one of Sheffield's most notorious 'Yardie' gangs last week.

But without a news agent's painstaking record keeping, the gang might have escaped justice.

In the first raid, police seized crack cocaine and heroin with a street value of £30,000. They also arrested Keidsha Williams, who was subsequently jailed, the BBC reports.

What they also found were a number of carbon paper 'customer copies' of money-transfer receipts from a Western Union agent in the Pitsmoor area of Sheffield.

Outstripped other agents

When other raids yielded similar receipts, detectives decided to take a closer look at this agent. He was Rajia Iqbal and his shop was known as Spital Hill News.

From the outside, it was nondescript; yet records showed that in one typical period - October to December 2004 - this agent was responsible for 11 per cent of the all the money sent via Moneygram to Jamaica from the U.K. Detectives mounted a three-month surveillance operation.

According to the BBC report, soon a pattern began to emerge. And though many of the names on the bills were unfamiliar, the faces were all too well-known to the police. On January 5, 2005, Rajia Iqbal was arrested and questioned.

A few weeks later, the police commandeered a hangar at Sheffield Airport for a dawn briefing before another series of raids. It was the only secure area considered large enough for the number of officers required for the coming operations, in which a large number of search warrants were carried out and numerous people arrested.

Over the coming months, the BBC reports, a huge mass of evidence was gathered. One officer, Det. Con. Andy Lintern, was responsible for following the paper trail from the U.K. to Jamaica.

Many of those arrested were Jamaican nationals, and with the help of the police based at Kingston, detectives managed to trace the owners of some of these houses.

But it was the detailed records recovered from Mr. Iqbal's money-transfer shop that ensured the conviction of the drug runners.