New Delhi: Former Uttar Pradesh Minister Anant Kumar Mishra was on Wednesday interrogated by the CBI in connection with alleged irregularities in expenditure of funds worth about Rs 10,000 crore in the National Rural Health Mission and murder of three top health officials.

Mishra, summoned by the central probe agency on Wednesday, was grilled for nearly eight hours during which he quizzed on expenditure incurred on various schemes, tendering process and procurement of ambulances for the state during his tenure as the Health Minister there.

He was also asked about the funds allocated under the scheme to Lucknow district and also on some developments which have surfaced during the probe in the murders of two Chief Medical Officers -- V K Arya and B P Singh -- which took place during his tenure as the Health Minister of the state, CBI sources said.

The agency had summoned Kushwaha and former Health Minister Anant Mishra here for questioning in connection with the multi-crore NRHM scam and murders of health officials which had led to state-wide furore over allegation of rampant corruption in execution of the central scheme, they said.

Kushwaha was questioned on Tuesday by the agency and is likely to be called again.

The CBI had started probe into the alleged irregularities in spending of Rs 10,000 crore allocated to Uttar Pradesh as central funds under NRHM, after registering five preliminary enquiries following orders of the High Court.