SILIVRI, Turkey — A Turkish court acquitted leading businessman and rights defender Osman Kavala on Tuesday in a highly controversial trial over the anti-government "Gezi Park" protests of 2013. The judge said there was "not enough concrete evidence" against Kavala and eight other suspects that appeared alongside him for the landmark verdict. Kavala received loud cheers from the packed courtroom as he walked free. "This is a trial that should have never happened in the first place," Emma Sinclair-Webb, of Human Rights Watch, told AFP at the courthouse in Silivri, on the outskirts of Istanbul. "This whole process has caused untold misery to those who were so wrongfully targeted, most of all Osman Kavala." Kavala spent more than 800 days in pre-trial detention and became a symbol of what critics say is a crackdown on Turkey"s civil society under President Recep Tayyip Erdogan in recent years. Seven other defendants, who are fugitives, were not formally acquitted. Prosecutors accused the group of 16 defendants, all leading civil society figures, of seeking to overthrow the government by orchestrating the mass protests that rocked the country in 2013. The demonstrations began over plans to demolish Gezi Park — one of the only green spaces in Istanbul"s center — but quickly spiralled into broader protests against Erdogan, then prime minister. Erdogan has called Kavala an agent of US financier George Soros, whose efforts to promote democracy around the world have made him a target for several authoritarian leaders. "Conspiracy theory" The European Court of Human Rights ruled in December that Kavala should be immediately released, saying the 657-page indictment against him lacked "facts, information or evidence" to raise even the suspicion that he helped organize the protests, let alone attempted to overthrow the government. "The bill of indictment... set out a conspiracy theory, devoid of ascertainable facts," it said. The Project on Middle East Democracy, a US-based advocacy group, said the case "made a mockery of due process and the rule of law" in a briefing note this week. Defense lawyers were denied the chance to cross-examine the key government witness, identified as Murat Papuc, when he gave evidence in December after he claimed his life was in danger. They also decried the inclusion of testimony from a police officer who was convicted of kicking a Gezi Park protester to death in July 2013, but who now claims he was a victim of the demonstrations. The defendants received support this week from Istanbul"s Mayor Ekrem Imamoglu, a high-profile opposition figure who took control of the city from the ruling party last year. "The decision to acquit all Gezi Park suspects is very positive and renews our trust in the judiciary. I salute all of those who, living in Istanbul, fight to protect the city"s history, culture, green spaces and nature," Imamoglu tweeted after the verdict. Kavala is chairman of the Anatolian Culture Foundation, which promotes human rights through art, including with neighbouring Armenia, with which Turkey has no diplomatic ties. — AFP