However, the actual reason to serve the notice is yet to to be known. It is learnt from the sources that Abhishek Banerjee has been asked to appear before the probe agency on a particular date in connection with the illegal coal mining scam.

"There's nothing new in it. The Bharatiya Janata Party (BJP) is trying everything to unseat the Trinamool Congress-led government in West Bengal. They are using central agencies to malign the image of Abhishek Banerjee before the forthcoming state Assembly election. The CBI notice is just a step towards that," Trinamool Congress spokesperson Kunal Ghosh said.

On February 2, the investigating team of CBI also went to Andal area and visited some open-cast mines at Kajora. They had conducted a detail probe into the illegal mining syndicate, carrying out raids in Asansol-Durgapur belt to collate more information about the illegal network.

Earlier on November 28 last year, the CBI's anti-corruption branch had conducted marathon raids in as many as 45 different locations in West Bengal, Bihar, Jharkhand and Uttar Pradesh in connection with a coal-smuggling racket. The federal agency had also raided the offices and homes of kingpin Anup Majhi, alias Lala, in Asansol, Durgapur, and Raniganj in Burdwan district, as well as at Bishnupur in Kolkata's adjoining South 24-Parganas district.