CBI sources said Singh was questioned in detail about his whereabouts on the day of incident in which village head Nanhe Yadav, his brother Suresh and Haq were allegedly murdered during violence arising over a land dispute on March 2.
They said the agency might also question his cousin and independent MLA Raghuraj Pratap Singh alias Raja Bhaiya in connection with these murders as some suspects are known to be cronies of the influential leader.
Recently, the agency has recovered a blood-stained wooden rod and ammunition belt with six live cartridges from various places here during its ongoing probe into the murder of Deputy Superintendent of Police Zia-ul-Haq and the two others.
The blood-stained ammunition belt was recovered from a box concealed in a house of Suresh Yadav, who was gunned down along with his brother and village pradhan Nanhe, official sources said.