A report by the Washington-based rights group, the International Campaign for Tibet, says the whereabouts of Gendun Choekyi Nyima are still a mystery. He and his parents were taken into custody by Chinese authorities in 1995, after the six-year-old boy was recognized by the Dalai Lama as the 11th Panchen Lama.
China selected another boy to be the Panchen Lama. That boy, Gyaltsen Norbu, was sent to study at Tashilhunpo monastery in Shigatse - the traditional seat for Tibet's second-most prominent figure.
The International Campaign for Tibet says the Panchen Lama's plight has come to symbolize the crisis facing the survival of Tibet's religious culture. It alleges that Beijing has been continuing to tighten control over religious practice and scholarship in Tibet.
Beijing's foreign ministry denies the allegation.
Some information for this report provided by AP, AFP and ICT.