West Bengal Chief Minister Mamata Banerjee on Tuesday visited her nephew and Trinamool Congress leader Abhishek Banerjee at his residence, ahead of the arrival of a Central Bureau Investigation team to question his wife in connection with an alleged coal scam case, ANI reported.

The chief minister met her nephew and his family for less than 10 minutes, according to NDTV. Moments after Mamata Banerjee’s convoy left, a team of around seven to eight CBI officers arrived to question Rujira Banerjee.

The central agency had served a notice to Rujira Banerjee on Sunday to join the inquiry. The next day, Rujira Banerjee responded, saying that though she was unaware of the reason why she was being questioned by the CBI, she was ready to be interrogated.

Abhishek Banerjee has alleged that he is being targeted by the BJP ahead of the state elections. “If they think they can use these ploys to intimidate us, they are mistaken,” he said in a tweet on Sunday. “We are not the ones who would ever be cowed down”.

The case pertains to illegal mining and theft of coal from leasehold mines of Eastern Coalfield Limited in Kunustoria and Kajora areas, and involves embezzlement of thousands of crores of rupees. It has been alleged that this smuggled coal was sold in the black market over a number of years by a racket operating in the western parts of the state.

The Bharatiya Janata Party has alleged that the kickbacks reached the Trinamool Congress MP through party leader Vinay Mishra. The party’s leaders have also claimed that Abhishek Banerjee channelled these funds into the Trinamool Congress.

In November last year, the central agency had filed a first information report against a person identified as Anup Manjhi, and Eastern Coalfield Limited General Managers Amit Kumar Dhar and Jayesh Chandra Rai. Others named in the FIR included its Chief of Security Tanmay Das, Area Security Inspector Kunustoria Dhananjay Rai and Security In-Charge Debashish Mukherjee.