The Central Bureau of Investigation on Saturday interrogated a Calcutta-based businessman in connection with its probe into the multi-crore coal pilferage scam, an official said.

Randhir Kumar Barnwal was quizzed by the CBI officers a day after the central agency raided his office premises and residence here.

The CBI had served a notice to him to appear before its Nizam Palace office here on Saturday for its investigation into the case, the official said.

Incidentally, the central agency and the Enforcement Directorate had on Friday conducted search operations at various places in West Bengal in connection with the scam.

Both the agencies are concurrently probing the illegal coal mining case.

The CBI is looking after the criminal aspect of it and the ED is delving into the money laundering angle of the scam.

A CBI team had examined Trinamool Congress MP Abhishek Banerjee's wife Rujira on Tuesday in connection with the coal pilferage case.

Earlier, searches were conducted at the residences and offices of people who are "considered close to Anup Majhi alias Lala" -- the main accused in the coal scam, the CBI official said.

Majhi has been absconding since the agency had initiated searches in connection with the case in November last year.

A lookout notice has been issued to Majhi to ascertain his whereabouts, as his interrogation was vital for the probe, the CBI had said earlier.

The central agency had, on November 28 last year, conducted raids at 45 places, including 25 in West Bengal, in connection with its investigation into the case.

Majhi is believed to be involved in the illegal coal mining in the Asansol-Raniganj belt of Eastern Coalfields Ltd.