No one knows why the writer named Lomig was detained or where he is.
He had helped to lead a protest urging the return of community land taken by Chinese authorities.
He will be taken into custody again when his term ends as monastery chant leader, authorities say.
Woman, 47, from Chokri Ngagong nunnery becomes 138th Tibetan to make fiery protest since 2009.
He wrote about the deployment of Chinese security forces in Tongren.
The monk was released after serving time for giving information to outside sources about the 2008 Tibet unrest.
The monk was released after serving a seven-year sentence for challenging Chinese rule in Tibet.
Tibetan protesters cycle through China's prison system, as some are released and others are taken into custody.
Chinese authorities forbid family and friends from holding a public reception welcoming his return.
His detention follows the roundup earlier this month of seven monks from the same monastery.
Authorities warn area residents against taking photos or filming videos of the monk's return to his home.
He had confronted Chinese officials over 'patriotic education' classes conducted at his monastery.
He was 'repeatedly tortured' and suffered ill health while in custody, sources say.
But a Tibetan monk is detained without explanation in neighboring Gansu
The monks are being held incommunicado, according to a source in exile.
Police detained him after he shouted slogans calling for “Freedom for Tibet.”
They reject Chinese government offers of assistance, throwing gifts of shoes onto the ground.