Verma, who was allegedly a key link between accused former Uttar Pradesh Family Welfare Minister Babu Singh Kushwaha and other actors in the scam, could have spilled beans about the nearly Rs5,000 crore scam, sources in the agency said.
He carried vital information about fund utilisation of the project, they said.
A NRHM project engineer with UP Jal Nigam subsidiary Construction and Design Services, 52-year Verma allegedly shot himself with his licensed revolver this morning at his Lucknow residence, making it the fourth mysterious death in the case.
He was named as an accused by the agency in a case of alleged irregularities in the upgradation of 134 hospitals in Uttar Pradesh and his residence was searched on January 4 but he was not called for questioning so far.
In the wake of the mysterious death of Verma, the CBI has sought report from Lucknow police about the incident.
Verma had been under depression after the CBI searches at his residence, family sources said.
The alleged suicide of Verma sent CBI officials in a tizzy and they refused to reveal the identity of officials being questioned in the case.
Continuing the questioning of officials at its headquarters in Delhi on Monday, the CBI grilled two senior officials each of UP Jal Nigam and UP Small Industries Corporation, the sources said without disclosing any names.