Senate has insisted the Comptroller General, of the Nigerian Customs Service, Hammed Ali must appear before it.
The lawmakers also insist Col.Ali must appear in the customs uniform.
Meanwhile, Ali has met with the President of the Senate, Bukola Saraki.
Details of the meeting which ended 7pm were not disclosed to journalists.
The embattled customs boss later wrote another letter to president of the senate, indicating his willingness to appear before the senators today, but without his uniform.
He also said the new customs duty payment on vehicles is being reviewed.