Calcutta: Four persons arrested on suspicion of carrying narcotics have been found to be involved in a kidney racket being allegedly run from a private hospital located off the Bypass.

"We arrested the four on the basis a tip-off that they were carrying drugs. We later found documents in their possession revealing the involvement of all four in a kidney racket at R.N. Tagore International Institute of Cardiac Sciences," additional commissioner (crime) Vishal Garg said in Lalbazar on Monday.

The hospital contested the allegation. "We would like to reiterate that our documentation processes and procedures are among the best in the country. Each kidney transplant is done at our facility with necessary government clearances, after due diligence," said a spokesperson for the hospital.

The police identified Ashfaque Ahmed, whose roots are in Kidderpore, as the kingpin. The other three are Tehrul Islam, 27, Baidyanath Burman, 38, and his wife Joshna, 36. They are allegedly organ donors from North Dinajpur.

Garg said officers of the detective department had acted on information about the group boarding a Howrah-bound train to reach the city last Friday. They were arrested at Anandapur. Brown sugar weighing 316gm - valued at a little over Rs 3 lakh - was allegedly found on them.

"On being interrogated, they confessed that Ashfaque had gone to north Bengal and brought the other three to sell their kidneys. He charges Rs 8-10 lakh for one kidney. The donors get Rs 3-4 lakh each."