A day after interrogating the owner of a Serampore nursing home in connection with gynaecologist Susil Pal’s murder, the Criminal Investigation Department (CID) on Sunday grilled three persons, including a doctor, working at the clinic. Police kept Swati Nursing Home closed on Sunday.

Pal was working at Serampore Walsh Hospital. He went missing on July 2 on his way to Serampore from his Calcutta residence on Broad Street. His body was found the next day on the bank of a canal in Sankrail.

Pal would also treat patients at the Serampore nursing home, owned by Gautam Chakrabarty. He stopped doing so a few days before his murder, following some differences with the authorities.

Police raided the clinic on Friday to find out if any unethical practices were being carried out there.

The doctor grilled on Sunday was asked about Pal’s relations with the nursing home authorities. “Apart from the doctor, nurses Anita and Bulbul have also been detained,” a CID officer said.

Police started suspecting the clinic-owner because of his persistent efforts to avoid them. “We haven’t come to know anything significant after questioning him. If necessary, we may summon him again,” the official said.

The sleuths are considering two possible reasons that may have led Pal to sever his links with the nursing home. They suspect Pal was forced to lure patients from neighbourhood nursing homes to Chakrabarty’s clinic and had earned a few enemies in the process.

This may have also given rise to business rivalry in the locality.

“Even though he was not attached to the clinic when he was murdered, we are investigating whether any past grudge was working against Pal,” a police officer said.

The other reason why Pal may have left the clinic was because he was forced to perform Caesarean operations even in cases where they were not necessary. Though doctors say this is a common practice, Pal, apparently, was reluctant to perform the operation because the nursing staff at the clinic was not trained for such surgery.

Police said the clinic authorities didn’t erase Pal’s name from the display board even after he quit. “The name was deleted a few days after Pal was murdered,” said an officer probing the case.