Bangladesh police said Tuesday they had busted a gang of suspected heroin smugglers who had been using international courier service DHL to ship drugs from Pakistan to London via Dhaka.

Five men are accused of using the method at least 60 times since 2008, sending drugs via the post to London using Bangladesh as a transit point, assistant police commissioner Touhidul Islam told AFP.

"A Bangladeshi immigrant in Birmingham leads the gang. He buys heroin from Pakistan and sends it to Bangladesh in courier services. The drug is then delivered to London mostly via courier services," Islam said.

"Most of the time they used DHL to ship the heroin to London," he said, according to information from one detainee, Shamsul Arefin, who is a cousin of the alleged ringleader.

The four others suspects work for a local courier service. They denied any wrongdoing and instead blamed Arefin for attempting to send heroin concealed inside the sole of a shoe in a package addressed to London.

"Arefin said they had been smuggling heroin in courier parcels for the last four years," Islam added.

Experts say Bangladesh is emerging as a new conduit for trafficking drugs to the West. A top tycoon is awaiting trial after being charged in 2006 with leading a racket that shipped large amounts of heroin to Britain.