Tzukte, popularly known as Asang, was taken into custody sometime in early July after he sang a song eulogising Tibet's exiled spiritual leader the Dalai Lama, the CTA said in a statement Saturday.

The CTA, which functions as a government-in-exile but is not officially recognised by any country, said the arrest was "part of Beijing's broader campaign to suppress Tibetan voices, specially Tibetan artists and writers".

China considers Tibet an inalienable part of its territory and has ruled the region with an iron fist since its troops crushed an uprising for autonomy in 1959.

Chinese authorities did not respond to a request for comment.

"His detention, without charge or information on his whereabouts, violates international human rights norms and underscores China's ongoing assault on freedom of expression, cultural rights, and religious belief in Tibet," the CTA said.

Asang, who is in his twenties, is a student of Gebe, a prominent Tibetan singer supporting the Tibetan cause through his music.

Earlier this year, Asang reportedly appeared in public in the Ngawa region of Sichuan province with the word "Tibet" written on his forehead -- a gesture that drew widespread praise online but also intensified scrutiny from officials.

Rights activists have regularly voiced alarm at Beijing's alleged efforts to erase cultural and religious identity in Tibet.