Controversy appears to be trailing the passage of the 2016 budget, as there are reports that the budget is missing.
A federal lawmaker, who spoke on condition of anonymity, told Channels Television that there were fears that the 2016 budget had disappeared from the National Assembly.
President Buhari on December 22 presented the 2016 budget to a joint session of the National Assembly.
The Senate on resumption of plenary on Tuesday went into a closed-door session which lasted for nearly two hours.
The lawmaker said the issue of the whereabouts of the budget was discussed during the closed door meeting.
The source further said the Senate had directed its Committee on Ethics and Privileges to investigate the matter.
But the Senate spokesman, Aliyu Abdullahi, in an interview with Channels Television said he was not aware that the 2016 budget was missing.
“To the best of my knowledge, I am not aware of any missing budget. What we discussed today is how we are going to work assiduously, as Senate of the Federal Republic of Nigeria to consider the budget as submitted by the president.
“Added to this, we have agreed that we should work hard to make sure that by the end of February the budget is ready for approval or assent by the President,” Mr Abdullahi stated.