The Senate Committee on Finance has rejected the representative sent by the Governor of the Central Bank of Nigeria, Godwin Emefiele.
The committee sent another invitation to him, insisting that he must appear before it.
Emefiele had on Monday sent one of his deputies, Adebisi Shonubi, to address the issue of the exchange rates for funding key projects but he was turned back by the committee.
The panel also blamed Emefiele for not informing it earlier that he would be sending a representative.
The CBN governor was therefore asked to appear before the panel again on Thursday.
Emefiele was expected at the Senate panel with detailed explanations on the rationale behind the exchange rates the CBN used for three key projects under the Presidential Infrastructure Development Fund.
The multi-billion-dollar projects are being funded by the Nigeria Sovereign Investment Authority.
The PIDF was earmarked from the dollar-denominated Sovereign Wealth Fund to partly finance the Lagos–Ibadan Expressway, Second Niger Bridge, Abuja–Kano Expressway, East-West Road and Mambilla Hydro Project.
The first three projects had already been funded to the tune of N163.8bn.