The Head of Service of the Federation, Winifred Oyo-Ita returned to office on Thursday following her notice of retirement.
It was gathered that President Buhari turned down her offer to quit.
Oyo-Ita who is under investigation by the Economic and Financial Crimes Commission over alleged financial infractions to the tune of N3bn had sent her letter of retirement to President Buhari at the weekend following pressure mounted on her.
Oyo-Ita had been absent from public functions after the EFCC grilling over allegations that she used front companies to get contracts when she was a permanent secretary before her appointment as head of civil service by Buhari in 2015.
She was also absent at the 2-day presidential retreat for ministers. But she was present on Wednesday at the swearing-in of ministers after meeting with the chief of staff to the president, Abba Kyari.