The unnatural death of GRP sub-inspector Arindam Manna who had first inquired into the death of Rizwanur Rehman, would not hinder the case of the computer graphics teacher, CBI officials claimed here today.

"He was merely the inquiry officer in the Rizwanur Rahman case. As there was no FIR at that time there is also no reason to term him as the investigating officer," the officials said of Manna whose body was found beside railway tracks at Mankundu station in Hooghly district on February 11.

The body of Rizwanur, who had married Priyanka, the daughter of industrialist Ashok Todi, was also found beside railway track on November 22 last year a month after his marriage. The police officer did the inquest before a magistrate and prepared the case diary.

"His death will not hinder the investigation or trial of the Rizwanur Rehman case whose trial is to start soon," the CBI officials said.

"As all documents are in black and white, they can be substantiated by any other officer," they said, claiming Manna was "not an important witness".

Asked under what circumstances Manna's death could be linked to Rizwanur case, the officials said "in case the local investigating agency arrests the Todis we will immediately take over the Manna (death) case.

The CBI is probing the Rizwanur case and the chargesheet has already been filed. Asked whether there was any scope for CBI to take over the case, the officials of the investigating agency said "if Rizwanur Rahman's family moves the high court and if the court orders the CBI to take over the (Manna) case then we will have to start investigation in the case."

Meanwhile, the Railways have initiated a departmental probe against the Officer-in-Charge of GRP, Sreerampore, Somnath Bhattacaharya who found Manna's body.

"A departmental inquiry has been initiated to probe why the post-mortem examination of Manna's body was conducted in a hurry. IG, Rail, A K Sarkar [Images] will conduct the inquiry and will submit the report soon. After that, action will be taken," Additional Director General (Railways) Dilip Mitra said.