The Central Bureau of Investigation (CBI) on Thursday sought permission from a special court for conducting a lie detection test on former Uttar Pradesh minister Raghuraj Pratap Singh alias Raja Bhaiya in connection with the murder of Kunda Deputy Superintendent of Police (DSP) Zia-ul-Haque.
The CBI reportedly wants to collect more evidence against Raja Bhaiya, one of the key accused in the case.
Raja Bhaiya was grilled by the CBI last month for over 20 hours, spread over a span of two days, but no credible evidence could be found to seek his custody.
The CBI is hoping that it can crack the murder case through the polygraph test.
Haque's wife Parveen Azad had accused Raja Bhaiya of being involved in the murder case.
The allegations forced him to resign from as Minister of Food and Civil Supplies from the Akhilesh Yadav government in March.
More From This Section
Haque was killed on March 2 in Pratapgarh district where he had gone to probe a village headman's murder.
An angry mob reportedly cornered him, and eight policemen who were with him allegedly abandoned him.
Three bullets were fired - one killed Haque; while another two killed headman Nanhe Yadav and his brother Suresh Yadav.
The CBI has registered four cases in connection with the three murders and booked Raja Bhaiya in one of them.
Raja Bhaiya, who has a lengthy criminal record, but has denied the allegations against him.
The CBI last month filed a chargesheet against five people but did not name Raja Bhaiya.