PATNA, Oct. 28 -- Taking cognisance of the questions raised by Buxar MP Sudhakar Singh, Bihar chief minister Samrat Chaudhary on Tuesday directed the principal secretary, state home department to investigate the matter and apprise the parliamentarian as well as the CM of the findings. This step is being seen as a big move amid the controversy since senior IPS officer Kundan Krishnan, who is presently DG Operations, served a legal notice to RJD MP Singh, threatening defamation suit of Rs.5 crore. The CM has entrusted the principal secretary of the Bihar home department with the responsibility of investigating the matter. A letter has been sent to the home department from the CM secretariat in this regard, said people aware of the development on Tuesday. The matter pertains to the suspicious death of Bharat Bhushan Tiwari in Bilauti village of Bhojpur district in June this year, and the subsequent demand to investigate the role of the police. RJD MP from Buxar Sudhakar Singh had demanded that the responsibility of senior police officers be fixed in this case. The matter escalated after Krishnan served him a legal notice and threatened defamation suit. Singh had also written to the CM as well as Lok Sabha Speaker Om Birla, questioning the legal notice on behalf of a serving government servant through a private legal firm without even the registration number of the lawyers. On Monday, the RJD MP again wrote to the Lok Sabha Speaker over his detention in Nawada, while he was raising the farmers' cause, which, he alleged, was done without any written order during the period when the Parliament session was on....