The Council of Europe on Tuesday told Georgia to improve its justice system, following allegations that the authorities were manipulating the law to conduct a politically-motivated crackdown on the opposition.
The timing of the criticism from the pan-European human rights body is critical for Georgia, as the country seeks to establish closer ties with NATO and EU following Russian annexation of Crimea in 2014.
Human Rights Commissioner for the Council of Europe Nils Muiznieks said in a report that Georgia had made some progress in overhauling its justice system, but added 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 the governor of the Odessa region.
Western countries have expressed concerns about the behaviour of his successors in the past amid allegations from the former president's supporters that they are being subjected to a political witch-hunt. The authorities deny the accusations.
Muiznieks also urged the government to tackle intolerance towards sexual minorities and to ease tensions between majority and minority religious groups in mainly Orthodox Christian Georgia.
NATO had been focusing on the region since 2008, when the Russian Federation supported the breakaway Georgian regions of South Ossetia and Abkhazia in a war which led to the regions declaring independence from Tiblisi.
The Council of Europe, based in Strasbourg, France, promotes human rights and democracy in Europe and has 47 member states.