The EU says an independent legal expert will investigate alleged corruption in the EU's rule of law mission in Kosovo.
The mission, called Eulex, is mired in allegations that some of its officials took bribes in return for dropping three cases involving organised crime.
A British prosecutor at Eulex, Maria Bamieh, was suspended after some secret Eulex documents were leaked.
EU foreign affairs chief Federica Mogherini will appoint an independent legal expert to probe Eulex.
"I intend to appoint as a matter of urgency an independent and experienced legal expert to review the mission's mandate implementation, with a particular focus on the handling of the allegations of corruption," Ms Mogherini told a news conference.
Ms Bamieh has accused two top Eulex officials of taking bribes from Kosovo criminals in return for dropping three prosecutions, including a murder case.
She said Eulex ignored her demands to open an investigation into the alleged corruption.
However, a statement on the Eulex website insists that "since 2013, Eulex and Kosovo judicial authorities have been pursuing a joint investigation into these allegations".
The mission was launched in 2008 in the wake of Kosovo's controversial declaration of independence from Serbia.
Eulex has a staff of 1,600 and tackles cases of organised crime, corruption and war crimes thought to be too sensitive for local justice officials to handle.
British Labour Party MEP Richard Howitt voiced concern about the allegations and said it appeared that the EU had failed to apply whistleblower protection procedures for Ms Bamieh.
"Eulex has done a lot and we want it to do more not less, but their and Europe's credibility is at stake," he said.
He led questioning for the Socialist group at the European Parliament, where two EU foreign affairs officials were asked about the allegations against Eulex on Monday.
He also voiced alarm at allegations that journalists had been threatened by Eulex officials.