A CID team on Sunday left for Dhanbad in Jharkhand to interrogate assistant sub-inspector of police Nagmani Singh, suspected to be involved in the kidnapping of a Surat-based industrialist’s son, Sohail Hingora from Daman, in October.

Nagmani, originally from Saran, was put under suspension after his name figured in a case lodged with the Nayagaon police station in the district. His son Ranjit Singh was earlier arrested and taken to Daman for his alleged involvement in Sohail’s kidnapping.

All senior police officers are tight-lipped and not willing to reveal the detention of Nagmani, who is said to have played an important role in the case. Apart from Ranjit, Nagmani’s three other sons — Deepak Singh, Santosh Singh and Sonu — have also been made accused in the case, sources said. The police had on Saturday arrested one Pankaj Kumar from Lakhisarai district.

So far, three persons — Ranjit Singh, Sabal Singh and Prem Prakash alias Som Prakash — have been arrested. While Sabal is a retired homeguard jawan, Som Prakash was an active member of the gang headed by Chandan Sonar. Sabal is the maternal uncle of Ranjit.

A driver, suspected to have dropped Sohail with his kidnappers to Ranjit’s house at Chuturpur in Saran district, was today picked up from Chechar village in Vaishali district for interrogation.

Another CID team carried out a raid on the house of one Gautam Kumar alias Kakku in Munger and seized some bank passbooks. Kumar is said to be a member of the gang led by Chandan Sonar.