Calcutta, July 28: The CID has unearthed a brown sugar manufacturing unit in a paddy field in Nadia, a rare discovery of a narcotics factory in the state in recent years.

On a tip-off from residents, sleuths raided a hut in the middle of the paddy field in Krishnagunj village two weeks ago and found nearly a litre of morphine in liquid form and 200gm of brown sugar. But the main suspect, Mohammad Raju, gave the police the slip.

The sleuths suspect the narcotics are sold in Calcutta and its outskirts.

Investigations have revealed that drug peddlers engaged racketeers from Uttar Pradesh and Rajasthan to convert poppy to morphine and heroin in the hut.

“The CID had never unearthed a heroin or brown sugar manufacturing unit before. We were surprised to see how a laboratory was set up in a small hut in the middle of a paddy field. The hut was set up in such a way that it seemed to have been built to keep an eye on the crops,” said Sanjay Mukherjee, special inspector-general of police, CID.

Farmer Sheikh Anwar, who owns the paddy field, is in police custody.

The CID has issued a notice to gram panchayat pradhans, warning them “they would be held responsible if anyone is found growing poppy or ganja in their areas”, Mukherjee said.

The CID has cracked down on poppy and ganja (cannabis) cultivation in Nadia, Murshidabad and Cooch Behar over the past one-and-a-half years. “We destroyed huge quantities of ganja and seized nearly 100kg,” said a CID official.

The sleuths had information that the brown sugar selling in Calcutta and adjoining areas was brought from Barabanki in Uttar Pradesh. “But the unit in Nadia made us sit up. There will be a crackdown on such units in the state,” an officer said.

According to the officers, the drug peddlers “hired manufacturers, who are known as ‘doctors’ in the circuit. The peddlers sell brown sugar of 25 to 30 per cent purity at a price of Rs 30 lakh a kg,” another officer said.

The investigators said the manufacturers probably targeted Calcutta and its fringe areas such as Tangra, Tiljala, Kasba, Jadavpur and Lake Town.

“There are some pockets (in Calcutta) where brown sugar in small packets, called purias, are available after dark. Most of those who take the purias are rag-pickers, beggars and street urchins who buy these for Rs 25 each,” Mukherjee said.