Sunil Dagga was apprehended by a CBI team in the capital, a CBI official said. The investigators are also on the look out for Ajay Garg, an alleged middle-man.
Meanwhile, three persons, arrested for their alleged role in the bribery case, were remanded in CBI custody till May 7 by a Delhi court.
Accused Narain Rao Manjunath, Managing Director of G G Tronics India Pvt Ltd and two others - Samir Sandhir and Rahul Yadav -- were produced before Special CBI Judge Swarana Kanta Sharma who sent them to CBI custody after the agency said that their custodial interrogation was required to unearth the entire conspiracy.
The CBI told the court that these accused were part of the deep rooted conspiracy and they need to interrogate them to confront them with the other arrested accused including Bansal's nephew Vijay Singla.
The court had yesterday remanded Singla and three others, Sandip Goyal, Dharmendra Kumar and Vivek Kumar, in CBI custody till May 7 after the agency said it was necessary to find out the "actual beneficiaries" and other conspirators who were involved in the bribery case.
The CBI has also arrested from Mumbai Mahesh Kumar, who is Member (staff) in Railway Board and is the main accused in the case, and he is yet to be brought to Delhi.
The CBI has arrested them for their alleged roles in the bribe case in which a deal of Rs 10 crore was finalised for fixing a top level position in the Railway Board.
The agency had said that it had received information that Manjunath was in regular contact with accused Mahesh Kumar who was trying to get himself appointed to a more lucrative post in Railway Board as Member (Electrical).
Mahesh Kumar, who was GM (West) Railways, had been promoted as Member (Staff) in Railway Board and was allegedly trying to get himself posted as Member (Electrical) in Railway Board, it said.