Upon resumption on Tuesday, the president held separate meetings with Abubakar Malami, attorney-general of the federation, and Maikanti Baru, group managing director (GMD) of the Nigerian National Petroleum Cooperation (NNPC).
The absence of Buhari at key government functions had fuelled speculations about his health, with critics mounting pressure on him to step down.
Civil society groups have also called on the president to go on urgent medical leave.
Malami addressed state house correspondents after meeting with the president., who is a member of the Presidential committee investigating suspended Secretary to the Government of the General of the Federation, SGF,
He said the final report of the committee probing Babachir Lawal, suspended secretary to the government of the federation (SGF), Ayo Oke, director-general of the National Intelligence Agency (NIA), would submit its report on Tuesday.
However, he refused to speak on whether the committee would yield to the calls of not making the report public.