The U.S. Department of Justice has described as “misleading” any implication that it had closed a probe into alleged corruption by Italian energy major Eni for lack of evidence and said the investigation could be re-opened if circumstances changed.

Eni, the biggest foreign oil and gas producer in Africa, is currently on trial in Milan on graft allegations surrounding the 2011 acquisition of a giant Nigerian oilfield.

It has also been involved in a long-running corruption case involving its previously 43%-owned unit Saipem over alleged bribes paid to win contracts in Algeria. A Milan court acquitted it last year but the decision is subject to appeal.

Separately, the U.S. Department of Justice (DoJ) had been conducting its own investigation into the Nigerian and Algerian allegations independently of the Italian court cases.

On Tuesday, Eni issued a statement saying the DoJ had informed it that the investigation had been closed with no action taken.

Following Eni’s statement, Italian prosecutors wrote to the DoJ seeking clarification and asking if the decision to close the inquiry was due to lack of evidence, as they said Eni’s statement seemed to imply.

According to a reply filed with the court in Milan and seen by Reuters on Wednesday, a trial attorney for the DOJ said that in light of the “misleading implication” of a lack of evidence highlighted by the prosecutors, he was sending them a copy of the DOJ’s original communication with Eni’s counsel in the United States.

In that letter, the acting chief of the DOJ’s Foreign Corrupt Practices Act unit said the inquiries had been closed because Italian authorities were prosecuting the case.

“If the circumstances noted above change, the Department may reopen its inquiries,” he said.

Shortly after issuing its first English language statement on Tuesday, Eni issued a second version with a slightly different wording that removed a passage saying the DoJ decision confirmed investigations by independent advisers and Eni’s own controlling bodies that found no illegal activity.

An Eni spokesman said the original statement had contained a translation error and had been replaced as soon as possible. He said the DoJ’s statement that it could re-open the investigation if circumstances changed was in line with normal procedure.

“If the DoJ would decide to reopen its investigation based on events new and unknown, then Eni will cooperate again with the Department to further demonstrate that Eni and its management are not involved in any illegal conduct,” the spokesman said in an emailed statement.

On Wednesday, Royal Dutch Shell, which is also on trial over allegations surrounding the acquisition of the OPL 245 field in Nigeria, said it had been informed that the DoJ had closed its inquiry into Shell over the deal.