Dharamshala, Sept. 15 -- The Central Bureau of Investigation (CBI) on Sunday arrested suspended assistant sub-inspector (ASI) Pankaj Sharma in connection with the mysterious death of Himachal Pradesh Power Corporation Ltd (HPPCL) chief engineer Vimal Negi. This is the first arrest in this case. It is being alleged that Sharma had tampered with a pen drive recovered from Negi's body - a key piece of evidence in the case. Negi had gone missing on March 10 this year and his body was found in a lake in Bilaspur eight days later. His wife had claimed that Negi had been facing continued harassment from his seniors. As per the allegations, ASI Sharma had hidden the pen drive recovered from Negi's body and formatted it. The ASI was under police protection for the last 90 days before it was revoked last week. A senior CBI officer, requesting anonymity, confirmed, "ASI Pankaj Sharma was arrested on Sunday. He will be presented before the special CBI court tomorrow. The investigation is still on." Negi's post-mortem revealed he had died approximately five days before the body was found, suggesting he may have been alive until around March 13. However, the special investigation team (SIT) constituted by the Himachal Pradesh Police failed to account for his movements between March 10 and 14, raising concerns about the effectiveness and transparency of the initial probe. The matter was handed over to the CBI on the directions of Himachal high court on May 23....