The ransom call to slain doctor Jayanta Ghosh's family on Tuesday morning was only a red herring, aimed at diverting the attention of the police, Criminal Investigation Department (CID) officers said on Wednesday.
The sleuths have also come to know that the mobile phone from which the call was made belongs to a doctor known to Ghosh.
Hours after kicking off their probe into the murder of 62-year-old Ghosh, a resident of Salt Lake's GD block, police have come across leads that seem to substantiate their hunch that the doctor was murdered because he had refused to take up a 'complicated gynaecological case', even against a hefty payment.
Had he been abducted for money ' the ransom caller had demanded Rs 2 lakh ' the kidnappers would have waited and given time to Ghosh's family to arrange the amount or negotiate, said an officer working on the case.
What clinches the sleuths' suspicion that the demand for money was only a cover-up is the fact that the call had come around 8.30 on Tuesday morning, almost an hour after the doctor had died.
His throat slit, Ghosh was dumped on a bridge on the Mayurakshi near Sandarpur village in Murshidabad, around 250 km from Calcutta, early on Tuesday.
On Monday afternoon, two persons in their 40s had barged into his chamber on Raja Manindra Road, in north Calcutta, and apparently asked him to visit a patient nearby.
CID officers are interrogating the Lake Town-based doctor from whose mobile phone the ransom call was reportedly made and also the owner of an STD booth in Kalyani, from where a call was made to Ghosh's wife Anima on Monday afternoon, informing her that he would be late.
Ghosh knew the doctor from his repeated visits to Belur ' he used to go there every Tuesday and Thursday and spend hours treating the poor, even handing out medicines to them.
The doctor was a student at National Medical College and Hospital when Ghosh was a teacher of anatomy there.
A preliminary probe suggests that the doctor lives off money that his married daughter provides. He was a regular at the place in Belur that Ghosh would frequent.
His phone number was recorded on the CLI in Ghosh's home. His wife conveyed the number to Tallah police and then to Gyanwant Singh, deputy commissioner (I), detective department.
On Singh's advice, one of the family members called the number. The doctor himself responded.
The owner of the STD booth in Kalyani has told police that he could identify the youth who woke him up on Monday afternoon and made the call to Ghosh's home.
'The booth is of a private telephone service provider. The owner said the youth had come alone and took the handset to a distance before making the call. He has offered some details which will be useful to us,' said a CID officer.