ISTANBUL — Ayse Bugra, the wife of jailed Turkish civil society leader Osman Kavala, said a new indictment accusing him of involvement in a failed military coup has shaken her belief that he can receive a fair trial and his years-long incarceration has been “torture” for their family.

Kavala, who worked on cultural heritage projects and efforts to reconcile Turks with Kurds and Armenians, has spent almost three years in prison without a conviction. Last week, an Istanbul court accepted an indictment that seeks a life sentence without the possibility of parole for Kavala, who marked his 63rd birthday behind bars this month, and an additional 20 years for espionage.

The fresh charges come eight months after another court acquitted Kavala and eight others after prosecutors failed to prove they tried to overthrow the government during protests to save Istanbul’s Gezi Park from demolition that mushroomed into nationwide anti-government protests in 2013. Within hours of Kavala’s acquittal, prosecutors came up with new charges, pre-empting his release.

Turkey has ignored a European Court of Human Rights order to free Kavala in December, when the Strasbourg court found his lengthy detention was unlawful, and the country’s top court last month indefinitely postponed his appeal against his imprisonment to await the new indictment.