Earlier, NAIJ.com reported an anti-corruption group, Say No Campaign, called for probe into the certificate scandals involving Senator Ademola Adeleke and the minister of finance, Adeosun.
In her statement on Friday, Adeosun said her understanding was that she was exempted from the scheme because she had moved back to Nigeria from Britain, where she was born, after she had passed the required minimum age.
Sources quoted her as saying, she had to go because the alleged forgery of her National Youth Service Corps Certificate made her position as Minister untenable.
The dual Nigerian and British national did not initially comment on the claims, leading to criticism from her opponents.
Adeosun was appointed by Buhari to manage the finances of Africa's biggest economy in November 2015.
Buhari also approved that the Minister of State Budget and National Planning, Mrs. Zainab Ahmed, should oversee the ministry immediately. Nigeria, Africa's most populous nation with almost 200 million inhabitants, is scheduled to hold general elections in February, with Buhari seeking a second term.