Dharamsala, Oct 18 : Tibetan political prisoner Tanak Jigme Sangpo, who had been in Switzerland since receiving political asylum in 2003 a year after he completed 37-year sentence at Chinese prison, has died at the age of 91, the Central Tibetan Administration (CTA) said on Sunday. According to the CTA, he died on Saturday. Extending condolences, CTA President Lobsang Sangay said: "I have been an admirer of his courage since my youth days. It was an honour meeting him in person and I also took part in the launch of his autobiography in Dharamsala. We have lost a true patriot of Tibet." According to the CTA, Sangpo was reportedly first arrested in 1960 while teaching at Lhasa Primary School and charged with "corrupting the minds of children with reactionary ideas". In 1964, he was sentenced to three years' imprisonment in Sangyip Prison over comments regarding Chinese repression of Tibetans and was sent to labour camp in Lhasa. He was again sentenced to 10 years' imprisonment in Sangyip Prison for 'counter-revolutionary' propaganda in 1970. He had been caught attempting to send a document reporting Chinese atrocities to His Holiness the Dalai Lama via his niece, who was trying to flee Tibet. Sangpo lost his eyesight as a result of suffering forced labour, prison atrocities and harsh prison conditions. "Torture and degrading ill-treatment, inhuman interrogation, solitary confinement, forced labour and indoctrination sessions are common practices used by the Chinese authorities in Tibet's prisons," he testified in 2003. As a result of sustained efforts by the CTA and international community pressing the Chinese government for his release, he was released on medical parole at the age of 76 in March 2002. In August 2002, he settled in Switzerland as a political refugee and relentlessly advocated for the issue of Tibet and testified at various human rights forums on the gross violations of human rights in Chinese-occupied Tibet, according to the CTA. In April 2003, Sangpo first testified at the UN Commission on Human Rights, in which he said: "This old man from Tibet, appeals to all nations in this hall to help end the human suffering of the Tibetans. "Please urge the Chinese government to open earnest negotiations with His Holiness the Dalai Lama to resolve the long-standing Tibetan issue in the interest of both the Tibetan and Chinese peoples." On June 5, 2008, he addressed the UN Council. Sangpo's biography titled 'Metse Nyongtsor' was released in January 2014 in Dharamsala by Sangay. It was published by Gu Chu Sum Movement of Tibet. /IANS