Meanwhile, senior BJP leaders in New Delhi have also pushed for a similar demand.
Bansal's nephew was caught red-handed taking bribe of Rs 90 lakh on behalf of a senior railway officer who wanted a "lucrative" posting at about 7 pm along with Sandeep Goyal, also said to be Bansal's relative, on Friday.
The CBI also arrested Mahesh Kumar, a railway board member (staff), soon after he landed at the Mumbai airport from Delhi on charges of paying the first instalment of Rs. 90 lakh meant for Singla. The deal was allegedly struck for Rs. 2 crore.
According to the CBI, Bangalore-based Manjunath, who appeared to have mobilised the money on behalf of the railway board member, has also been named in the FIR along with Goyal.
Bansalm, however, has denied any business links with Singla and denied any wrongdoing.