Ashish Patel-owned AM Car and Van Hire company was engaged during QBR in 2009 to provide services like taxis for the guests and OC members, while the AM films was hired to provide display monitors during the event.
The agency was banking on Patel to provide details of alleged conspiracy involving officials of the Commonwealth Games Organising Committee, and his turning into approver would have given "crucial" fillip to the CBI''s case, sources said.
Senior CBI officials, however, claimed that Patel could have been an important element in proving conspiracy and money trail but even his non-cooperation will not affect the case much.
The CBI had last month sent a two-member team comprising Additional Director V K Gupta and DIG S K Palsania to London to probe the payments made to the two companies allegedly with Kalmadi''s tacit approval, they said.
The agency tried to contact Patel through informal channels where he had agreed to cooperate in the probe but he seemed to have change his stance now, sources claimed.
The CBI team during their visit to London had also questioned other companies which were in the fray for the contract, sources said.