There are over 0.5million heroin addicts in Pakistan, out of which, 10 percent take the drug intravenously. A United Nation report said thousands of people were swelling the ranks of heroin addicts in Pakistan, threatening social dysfunction and the spread of Aids through shared contaminated needles.
The head of Pakistan's Anti-Narcotics Force (ANF), Major General Nadeem Ahmed, however said an eradication drive was in progress.
He said the total area in Pakistan under opium poppy cultivation was significantly down on last year's level. He told BBC just about 3,000 hectares was yielding poppies, against 6,700 last year.
General Nadeem promised to step up the eradication campaign, particularly in north-west Frontier Province, saying the Americans were linking development aid to its success. Due to lack of resources, ANF and other law enforcement agencies were not adequately catered to take on the threat, he added.
What worries him more, however, is the likely impact of surge in opium production in neighbouring Afghanistan.
Around 70percent heroin is smuggled to markets in Western Europe and Japan through Pakistan and Iran and 30percent consumed in Pakistan. Most of the opium is first refined into heroin before it is smuggled along routes the Balochistan province.
"It's an immense area, even if we have a squadron of helicopters that would be insufficient," says General Nadeem adding that ANF had one, old, Russian-built helicopter funded by the British, to patrol a border 1200-km long.
To a question, ANF chief said the link of opium with militant funding had yet to be proved. The current direct funding from the Americans and the British amounted to just over $3million - a drop in the ocean compared to the hundreds of millions being pledged to Afghanistan.
General Nadeem further said that his operations had been further hampered by the fact that forces from the much larger paramilitary Frontier Corps, who backed up ANF-led operations, had been diverted to the fight against al Qaeda-linked militants in the tribal areas.
"In 2003, we seized 34 tonnes of heroin or its equivalent. In 2004 because of the operations in bordering areas of Balochistan and North-West Frontier Province, our seizures came down to 25 tonnes," General Nadeem pointed out.
"If the Frontier Corps is relieved from those duties, I think our capacity would be greatly enhanced" he added.
According to United Nations statistics, 130,000 hectares in Afghanistan were producing opium poppies in 2004.
But officials say it is still disturbing, because just a few years ago Pakistan was declared free of opium poppies after a long campaign.