Police have launched a probe into the alleged abduction of 16-year-old Sneha Nasaria from Ranchi after her parents received ransom calls from Calcutta.

Daughter of businessman T.K. Nasaria, Sneha disappeared in the middle of October. A week ago, the Nasarias received ransom calls twice. The family immediately passed on the numbers to Jharkhand Police, who came to know after an inquiry that the ?abductors? had called from Calcutta.

Though senior officers refused comment, sources said Tollygunge police station and the detective department are probing the case. Teams have fanned out across south Calcutta and calls from select booths are being monitored.

The calls to the Nasarias were made from PCOs ? one on Tollygunge Road and the other on SR Das Road, in Mudiali. Sleuths grilled the owners of both booths, hoping they would be able to throw light on the those who had made the calls. But both owners pleaded helplessness.

The cops, nevertheless, have stepped up vigil and are monitoring calls made by gangs known to have Jharkhand links.

Officers overseeing the probe have not ruled out the possibility of Sneha leaving home on her own. Some of them even suspect she has an affair and that she had left home with her boyfriend.

Such suspicions stem from the fact that, according to Jharkhand Police, no one had seen her being abducted. (This has left police with no clue what the kidnappers look like.)

Cops believe Sneha had possibly walked out with someone she knew.

Had she raised an alarm, which she would surely have if she had been abducted, her neighbours or passersby would have witnessed the incident.

Soon after Sneha went missing, her parents looked for her at her relatives? homes. They lodged a complaint with police only after their search proved futile.

It was on advice from senior officers that they had attached the caller line identification machine to their phone. This enabled them to note the numbers the ransom calls were made from.