The EU executive on Wednesday expressed concern about developments in Turkey where the government is embroiled in a massive graft scandal that has triggered a purge of the police Hurriyet Daily News reported.
Asked to respond to events in Turkey, a spokesman for the European Commission said "recent developments" in the country were "a cause of concern."
"We urge Turkey, as a candidate country committed to the political criteria of accession, including the application of the rule of law, to take all the necessary measures to ensure that allegations of wrongdoing are addressed without discrimination or preference in a transparent and impartial manner," said a Commission statement.
"Any action which undermines the effectiveness of investigations into these allegations should be avoided."
Twenty-four people have been arrested as part of a massive corruption investigation that emerged in Turkey last month, including the sons of former Interior Minister Muammer Guler and former Economy Minister Zafer Caglayan.
Turkish Prime Minister Recep Tayyip Erdogan has cast the corruption investigations as an attempted "judicial coup" by forces seeking to undermine his government, and hundreds of police officers have been removed from their posts.
The fighting via probes and dismissals highlights the deepening conflict between the ruling AKP and the Gulen movement, the followers of which are said to hold key positions inside the secret services, the police and the judiciary, and who are believed to be behind the investigation.
"The recent steps (removing, reassigning or firing police officers and investigators) are a matter of concern," the EU text said. "These steps could undermine the current investigations and capacity of the judiciary and the police to investigate matters in an independent manner."