The court ordered Kavala’s release from detention in a high-profile trial was closely watched by rights groups, who had accused the Turkish government of using the judicial system to crack down on dissenting voices.
The new order issued by the Istanbul Chief Public Prosecutor’s Office seeks to keep Kavala in detention over the failed military coup in 2016.
In a statement, the organization said the “judgement was a touchstone for Turkish justice.”
Kavala, along with two other defendants, had faced life sentences for allegedly attempting to overthrow the government.
Seven of the 16 defendants in the case are living abroad and were being tried in absentia. Arrest warrants for those seven have been lifted, and they are expected to be officially acquitted if they return to Turkey.
Kavala has always maintained he took part in a peaceful demonstration to save the green space in central Istanbul from developers.
In December last year, the European Court of Human Rights ruled Kavala had been arbitrarily detained.
What were the 2013 protests about?
The Gezi Park protests almost seven years ago involved sit-ins by conservationists and campaigners in and around the park.
Scenes of riot police brandishing tear gas and water cannons at young protesters were broadcast on televisions around the world. The protests soon became about a broader discontent with Turkey’s increasingly authoritarian government.
CNN’s Jomana Karadsheh reported from Istanbul and Sheena McKenzie reported from London. CNN’s Mostafa Salem and Angela Dewan contributed to this report.