An official in Nigeria says the new president's wealth declaration shows that he has been living "an austere and Spartan lifestyle" compared to his predecessors and other senior government officials, with $150,000 in his personal account.

Garba Sehu, a senior special assistant in charge of media and publicity for the president, said in a statement that documents submitted to the Code of Conduct Bureau show President Muhammadu Buhari's lifestyle is contrary to what one would expect of a top official.

Sehu says the documents submitted to the bureau are still being vetted but will soon be made public. Buhari has vowed to stamp out corruption which is endemic in Africa's biggest economy.