CID officers on Tuesday interrogated a doctor who was attached to Sree Krishna Nursing Home for 22 years after his name cropped up in the baby-sale racket.

The doctor lives in Salt Lake and was with the MG Road nursing home from 1990 to 2012, police said. He was questioned for over six hours at the agency's headquarters in Bhabani Bhavan. He's been called again on Wednesday, an officer said.

Gynaecologist Santosh Kumar Samanta, 60, who has been arrested in connection with the racket took over from the doctor in 2012.

Partha Chatterjee, the owner of the nursing home, and his daughter-in-law Paramita Chatterjee, the administrator, are now in CID custody.

"We got to know of the doctor while interrogating Samanta. Sree Krishna on 55 MG Road has been involved in infant trafficking for over 20 years. We suspect this doctor of having had a key role in the racket," a CID officer said.

Samanta has said he got into this business seeing the doctor who was his predecessor, another officer claimed.

A nursing home in Basanti, South 24-Parganas, is under the CID scanner. "A similar racket is being run there. Investigations are on," the officer said.

Newborns found

Three newborns were found on the banks of a canal in Tentulia in the Khardah police station area on Tuesday night.

"We are yet to ascertain if the babies are part of the racket," a CID officer said.

Midnapore arrests

A help at Midnapore Medical College and Hospital was arrested on Tuesday when she tried to sell a three-day-old girl, the police said.

The baby's 16-year-old mother and grandparents, too, were arrested.

A woman officer posed as a prospective client before Shibani Ruidas, who promised her a child for Rs 20,000. "The deal was settled at Rs 5,000. Ruidas was arrested when she gave the officer the baby and demanded money," an officer said.