The U.S. government allegedly gave Nigeria’s President Muhammadu Buhari the names of Nigerian oil thieves who have been stealing and illegally stockpiling the West African nation’s oil. U.S. President Barack Obama’s administration provided Buhari with the names last week when the Nigerian leader was visiting the White House, according to a Nigerian newspaper that cited presidential sources.

A member of the Nigerian president’s entourage told the Punch that Buhari was shocked by the names, and it could prompt him to probe the administration of former Nigerian President Goodluck Jonathan, who was widely accused of corruption. “I can tell you that the president already has the list of names of the people engaging in the stealing of Nigeria’s oil. The list, when released by the president, will shock Nigerians,” the source, who reportedly spoke on condition of anonymity, told the newspaper on Tuesday.

A second unnamed source within Buhari’s administration confirmed with the Punch that Buhari was given the names of top Nigerian government officials who were abusing their power to loot the country’s oil, as well as the names of illegal oil hoarders. “The president will probe all of them and make sure they return whatever fortune they made from their thievery,” the source, who also spoke on condition of anonymity, told the Punch on Tuesday.

Muhammadu Buhari and Barack Obama U.S. President Barack Obama (right) meets with Nigerian President Muhammadu Buhari (left) in the Oval Office of the White House on July 20, 2015 in Washington, DC. The two leaders discussed various topics including Nigeria's economy, corruption and the fight against the Boko Haram terrorist group. Photo: Alex Wong/Getty Images

The Nigerian leader, who took office on May 29, has vowed to clean up corruption from previous administrations and to hold perpetrators fully accountable. Last week, Buhari said about 250,000 barrels of crude oil are stolen each day in Nigeria, Africa’s largest oil producer, and that some former ministers sold as much as 1 million barrels per day. He had asked Obama to help locate and return $150 billion believed to have been stolen by corrupt government officials, according to Bloomberg. The two leaders met at the White House in Washington last week for talks on Nigeria's economy, corruption and Islamist militant group Boko Haram, among other topics.

“The amount involved is mind-boggling,” Buhari said of the oil scandal on July 21, according to a statement from his office. “A lot of damage has been done to the integrity of Nigeria with individuals and institutions already compromised.”

Jonathan conceded power to Buhari immediately after losing the March presidential election, marking the first time an incumbent didn't declare victory in Nigeria. But some members of Jonathan’s administration were slow to provide handover notes to Buhari’s incoming government, making the transfer of power less smooth.

Jonathan’s political faction, the once-ruling Peoples Democratic Party, said it supports Buhari’s commitment to fight corruption but that due process must follow.

“The PDP supports the decision of the federal government to fight corruption in our country. However, we make bold to state that it should not be disguised to victimize innocent citizens. Democracy has come to stay in Nigeria and no citizen, irrespective of political, religious or ethnic affiliation should be denied access to due process and the rule of law in the process,” PDP spokesman Olisa Metuh said in a statement on Tuesday. “Furthermore, we make bold to state that he who comes to equity must come with clean hands.”