The Council of Europe told Georgia on Tuesday to improve its justice system, saying it was worried about allegations that authorities have been abusing the law to conduct a politically motivated crackdown on the opposition.
The criticism from the pan-European human rights body comes at a sensitive time for Georgia, which has sought to move closer to NATO and the European Union in the wake of Russia's annexation of Ukraine's Crimea in 2014.
Georgia fought and lost a brief war with Russia in 2008 that ended with Moscow tightening its control over two breakaway Georgian regions, and it is keen to court the West as a potential counterbalance to Russian influence.
Nils Muiznieks, human rights commissioner for the Council of Europe, said in a report that Georgia had made some progress in overhauling its justice system, but that long-standing structural problems needed serious attention, particularly with a view to upholding the independence of the judiciary.
"The commissioner is concerned about allegations of politically motivated measures targeting members of the opposition, especially with regard to the use of pre-trial detention measures against them," he said.
Dozens of former officials who served ex-President Mikheil Saakashvili, including a former prime minister, have been arrested on charges such as abuse of power and corruption since Saakashvili's government lost power in 2012.
Wanted in Georgia on charges he abused his authority, Saakashvili currently lives in Ukraine, where he is governor of the Odessa region.
Western countries have expressed concerns about the behavior of his successors in the past amid allegations from the former president's supporters that they were being subjected to a political witch hunt. The authorities deny the accusations.
Muiznieks also urged the government to tackle intolerance toward sexual minorities and to ease tensions between majority and minority religious groups in mainly Orthodox Christian Georgia.
The Council of Europe, based in Strasbourg, France, promotes human rights and democracy in Europe and has 47 member states.