Qaidar Sarin, the chief of the labor camp AK 159/6 in the central Kazakh town of Dolinka, told RFE/RL on July 22 that Maksim Kozhanov "commited suicide fearing that his prison term might be prolonged."
Sarin said Kozhanov, 30, was the prisoner who videotaped on a mobile phone a "fake beating of an inmate, Yevgeny Karaush, by a person dressed as a jail guard."
The video clip appeared on the Internet in May and prompted outrage from viewers and human rights organizations.
Dolinka officials said at the time and continue to claim that the video is a fake.
In June, Karaush, Kozhanov, and several other inmates all slit open their abdomens to protest the pressure exerted on them by the prison authorities, some of their relatives told RFE/RL.
The injured inmates were brought to a hospital in the neighboring town of Shakhtinsk for treatment.
But Karaush's mother, Galina Dobrovolskaya, told RFE/RL on July 22 that the inmates were not given full treatment for their injuries. She said they were returned to Dolinka where they were placed in solitary confinement.
"They were still sick and weak, but were placed in solitary confinement and interrogated for several hours a day," she said.
Dobrovolskaya said the jail authorities had to transfer Kozhanov and another protester to the penitentiary hospital due to their physical condition. She said sometime around June 10, "Kozhanov was found hanged."
Dobrovolskaya said Sarin told her that Kozhanov was a drug addict who killed himself because he could not cope with withdrawal symptoms.