Nigerian President Muhammadu Buhari fired all eight executive directors of Nigeria’s state-run oil company, one day after appointing a new managing director. The sacked managers were appointed by former Nigerian President Goodluck Jonathan in March 2014, Reuters reported. Since taking office in May, Buhari has made clear his intentions to flush out corruption from past administrations.

"All of the executive directors were let go,” one of the dismissed executive directors told Reuters. “Buhari wanted a clean slate.”

Emmanuel Ibe Kachikwu, the new head of the Nigerian National Petroleum Corporation, delivered the bad news to the senior managers Wednesday after meeting with Buhari at the presidential villa in the capital Abuja, the Nigerian newspaper Thisday reported. An unnamed source told Reuters the number of executive director positions in the Nigerian National Petroleum Corporation would be reduced to four and the replacements were already approved by the president. The names of the new executive directors reportedly will be released later Thursday.

"The Federal Government has approved the retirement of all eight Group Executive Directors of the Nigerian National Petroleum Corporation (NNPC) with immediate effect," said an emailed statement from the state oil company, obtained by Reuters.

David Ige of NNPC David Ige, then-group executive director of gas and power of the Nigerian National Petroleum Corporation, speaks at the Nigeria Power Summit on Gas to Power: Optimising Supply, Infrastructure & Pricing, on March 17, 2014, in Abuja, Nigeria. Ige was fired along with the company's other executive directors on August 5, 2015. Photo: REUTERS/Afolabi Sotunde

In recent weeks, Buhari has moved to clear out corruption in the oil sector from previous administrations. The Nigerian leader on Tuesday chose Kachikwu, a former executive vice chairman at Exxon Mobil Africa, to replace Joseph Dawha, who was a Jonathan appointee. In June, Buhari disbanded the state oil company’s entire corporate board amid rampant allegations of theft.

The Nigerian National Petroleum Corporation has been increasingly withholding staggering sums of money from the Nigerian treasury and oil sale practices have worsened, an international governance watchdog claimed in a report released Tuesday. The company, which did not respond to requests for interviews, retained about $12.3 billion from the sale of 110 million barrels of oil over 10 years, the report said.

Before he defeated Jonathan at the polls, Buhari vowed on the campaign trail that he would crack down on graft and crooked politicians in oil-dependent Nigeria. The West African country is Africa’s largest economy and most populous nation, but has suffered from tumbling crude oil prices and large-scale corruption. Oil and gas exports account for more than two-thirds of the Nigerian government’s revenues.

Ahead of his presidential trip to the United States last month, Buhari asked U.S. President Barack Obama to help locate and retrieve the “mind-boggling” amount of lost oil funds. The Nigerian leader might also probe Jonathan’s administration, which was widely accused of corruption.

“The amount involved is mind-boggling,” Buhari said in July, Bloomberg reported. “A lot of damage has been done to the integrity of Nigeria with individuals and institutions already compromised.”