Nigeria's president on Wednesday suspended the country's intelligence chief over the recent discovery of $43 million in cash in a Lagos apartment.

President Muhammadu Buhari has ordered an investigation into how the National Intelligence Agency came to claim the money and whether any laws were broken, a government statement said.

The discovery of the cash in both local and foreign currencies by the country's anti-corruption commission caused a sensation in this West African nation where graft is rampant.

Buhari has ordered the suspension of the director-general of the intelligence agency, Ambassador Ayo Oke, until the investigation is complete, the statement said.

The investigation has been given two weeks to report to the president.

Separately, Buhari has ordered an investigation into alleged wrongdoing in the award of contracts under the government office that coordinates the humanitarian response in Nigeria's northeast, which for years has suffered from the Boko Haram insurgency.

Government secretary David Babachir Lawal allegedly diverted 800,000 dollars in government funds allocated to address the humanitarian crisis in the country's north-east, Femi Adesina, special advisor to the president, said in a statement.

Buhari won election in 2015 on a promise to halt corruption.

Nigeria is one of the most corrupt countries in the world, ranking 136 out of 176 countries, according to an index by non-profit organization Transparency International.