CBI sources said besides Singh and Rishi, two Delhi-based businessmen and two executives of Vectra--Managing Director Anil Mansharamani and Chief Financial Officer Vikram Kakaiya-- were questioned in detail at the agency headquarters.
The agency during its six-month long preliminary investigation has found prima facie evidence of links between Tejinder Singh and Ravinder Rishi, who is also a Director in Tatra Sipox UK--the company which was supplying allegedly substandard trucks, they alleged.
The sources said during its probe the name of a businessman having interests in pharmaceutical sector and his relative, who owned a leading pub in a five-star hotel, also cropped up and their residences were searched during agency's operation on Saturday.
They claimed the sleuths recovered Rs 98 lakh cash from the bedroom of the businessman.
The CBI is trying to ascertain whether the businessman acted as mediator between Tejinder Singh and Ravinder Rishi for felicitating any money transaction, they said.
CBI sources said although preliminary inquiry gave substantial prima-facie evidence of links between Singh, Rishi and the businessman but the actual relations shared by the trio would be established during the questioning and further investigations.
Singh did not respond to SMS sent seeking his reaction. More