Tibet's parliament-in-exile on Sunday called for Beijing to confirm the "well-being and whereabouts" of the Panchen Lama, the second-most important figure in Tibetan Buddhism's largest school, a quarter of a century after he disappeared.
The whereabouts of Gedhun Choekyi Nyima -- the boy recognised as the reincarnation of the Panchen Lama by the Dalai Lama on May 14, 1995 -- have not been known since he was taken into custody three days later by Chinese authorities aged six.
"China must provide verifiable information on the wellbeing and whereabouts of the 11th Panchen Lama," the Tibetan parliament-in-exile, which is based in Dharamsala in the foothills of the Indian Himalaya, said in a statement.
"The disappearance of the Panchen Lama is not only an injustice to one person, but it is an injustice to six million Tibetans and their right to religious freedom."
The US Thursday renewed calls on China -- which has appointed its own Panchen Lama -- to free the Tibetan, who rights activists have called the world's youngest political prisoner.
The Dalai Lama has made India his home since fleeing Tibet in 1959, and resides in Dharamsala in the north of the country.
In February he marked the 80th anniversary of his enthronement as the spiritual leader of Tibet, a position held almost entirely in exile and as a target of constant vilification by the Chinese state.
China's officially atheist government has said it could seek to name a successor to the 84-year-old Tibetan spiritual leader.
In 2015 the official Xinhua news agency quoted an official in Tibet as saying that the Panchen Lama was healthy, enjoying an education and "does not want to be disturbed".