Aisha Buhari, wife of President Muhammadu Buhari has warned that she may not back him at the next election unless he shakes up his government.
In a yet-to-be-aired BBC interview, Aisha Buhari said the president "does not know" most of the top officials he has appointed.
Mr Buhari was elected last year with a promise to tackle corruption and nepotism in government. His wife's decision to go public with her concerns is likely to shock many people, but is also seen as a sign of the level of discontent with the president's leadership.
She suggested the government had been hijacked, saying a "few people" were behind presidential appointments.
The president famously remarked at his inauguration that he "belongs to nobody and belongs to everybody".
In the interview with Naziru Mikailu, Mrs Buhari said: "The president does not know 45 out of 50, for example, of the people he appointed and I don't know them either, despite being his wife of 27 years."
She said people who did not share the vision of the ruling All Progressives Congress (APC) were now appointed to top posts because of the influence a "few people" wield.
"Some people are sitting down in their homes folding their arms only for them to be called to come and head an agency or a ministerial position."
Asked to name those who had hijacked the government, she refused, saying: "You will know them if you watch television."