Why was Sushil Pal murdered? That — and not ‘was Sushil Pal murdered’ — is the question sleuths are grappling with three days after the Bright Street doctor’s body was found near a canal in Howrah.

Wife Kanika Pal lodged a formal murder case with Sankrail police station on Tuesday before the matter was handed over to the Criminal Investigation Department (CID) at the behest of director-general of police Shyamal Dutta.

With the post-mortem report revealing that Sushil Pal was “brutally beaten up and strangled to death” before his body was dumped from a bridge over Saraswati canal at Sankrail, police are trying to piece together the method behind the murderous act.

“The post-mortem report says that Pal was showered with kicks and blows by his assailants — resulting in a damaged kidney — and hit on the back of his head with a blunt weapon before he was strangled to death. The brutality of the murder suggests that there were more than one assailants and it was not for monetary gain. It could possibly be a revenge killing,” said an officer on the case.

Was it because the gynaecologist was caught up in a tussle with some city-based promoters? Or was he targeted for being a witness in a rape case during his stint in Jalpaiguri?

When Pal left home on Friday around 8 am, he told his wife that he was heading for Walsh Hospital in Serampore, where he was a gynaecologist. But the hospital authorities said Pal had not turned up for work.

Superintendent of Walsh Hospital T.K. Nandi suggested on Tuesday that Pal’s murder could have something to do with his being a prime witness in a rape case.

“It was only a month ago that Pal had received a court order asking him to appear at the Jalpaiguri court, but he had let the court know that he would not be available on that day because of his commitments here,” revealed Nandi.

Police are not ruling out the realtor angle. They are trying to figure out if a promoter, who was to have developed a property of Pal’s late father-in-law Malay Pal on Linton Street, can throw some light on murky matter.

“When Pal arrived in Calcutta from Jalpaiguri three months ago, after his father-in-law’s death, he decided to call off the deal and, instead, build a nursing home at the site,” sleuths on the case said.