Osman Kavala, imprisoned in Turkey for nearly three years without ever being convicted of a crime, is a philanthropist and businessman who supporters say has tirelessly used his wealth to help society.
The 62-year-old marked 1,000 days behind bars on Monday, prompting a fresh round of support on social media under the hashtag #FreeOsmanKavala.
Little-known to the public before his arrest, he has become a symbol of what critics say is a crackdown on civil society under President Recep Tayyip Erdogan, especially in the wake of a failed coup in 2016.
Initially, Kavala was accused of fomenting the so-called Gezi Park protests in 2013, but when he was acquitted on those charges in February, he was immediately re-arrested over claims he was involved in the coup.
He is now accused of seeking to overthrow the constitutional order and espionage.
"We've had 1,000 days stolen from our life," his wife, Ayse Bugra, said during an online press conference on Saturday.
"My husband's mother is over the age of 90 and she doesn't know whether she will ever see her son again," she added.
The US State Department on Monday urged Kavala's release, with spokesman Cale Brown calling for "a just, transparent and speedy resolution" of his case.
Kavala was excluded from a prisoner release in April in which thousands walked free as a safety measure against the coronavirus outbreak.
In a message in English from his cell in Silivri prison on the outskirts of Istanbul on Monday, Kavala criticised "unlawful practices in politically motivated cases.
"Despite all this, and despite being one of the individuals to feel the burden of this deteriorating situation, I have not lost my hope," he said.
Born in Paris in 1957, Kavala graduated from the University of Manchester after studying economics. He took over his father's business after his death in 1982.
He has supported art and social projects, and is seen as a bridge-builder between communities in a country that is often fiercely divided.
His friends describe him as humble but stubborn, polite but direct, bossy but never patronising.
"I would rather describe him as a colleague than a boss. Osman bey has never patronised us," Asena Gunal, director general of Anatolian Culture, told AFP, using an honorific title to show her respect for him.
Kavala is chairman of Anatolian Culture, or Anadolu Kultur in Turkish, which promotes human rights through art -- including with neighbouring Armenia, with which Turkey has no diplomatic ties.
"He has never boasted of his wealth but has a humble personality who feels embarrassed of whatever he owns," said Gunal at the Depo arts centre in Istanbul's upscale Tophane district, a former tobacco depot that Kavala inherited and restored.
Umit Kivanc, an author whose friendship with Kavala dates back over 40 years, dismissed caricatures of him as a wealthy bourgeois man.
"Rich, bourgeois, businessman? No, Osman is a stubborn leftist," said Kivanc.
"He's a man who works for justice in the world... (But) Turkey is a land that chips away at everything that is good."
The court in February ruled there was no evidence showing that Kavala financed the Gezi Park protests in 2013, which began over plans to urbanise a rare green space in the heart of Istanbul before spiralling into widespread anti-government demonstrations.
He was the only one of nine defendants kept in jail throughout the trial.
Shortly after his acquittal, Kavala faced two fresh arrest warrants including espionage charges, which he deemed as "more ridiculous than the previous" accusations.
"He is the last person to support any coup attempt and it is truly appalling to see him targeted as he has been and made the pawn in some incomprehensible political game," said Emma Sinclair-Webb of Human Rights Watch.
Burhan Sonmez, a member of PEN International, recalled one touching moment when Kavala asked him to tell foreign supporters not to attend one of his key hearings on December 24, saying they should spend Christmas Eve with their families and friends.
© Agence France-Presse