Police have now blocked communications in the area to keep more news from getting out.
Woechung Gyatso was taken into custody after participating in a Chinese-led workshop on laws regulating internet use.
Meetings with a Chinese embassy official in Poland and a journalist in Sweden were unconnected with intelligence work, he says.
Local Tibetans lose land they have farmed for generations, with compensation paid at below-market rates.
Lhamo Dolkar, 60, came under suspicion after she visited a political prisoner in jail some six years before her detention.
The suspect is believed to have been paid by Chinese agents for information about the diaspora.
It was Labrang monk Jinpa Gyatso's second period of incommunicado detention in less than a month.
Listed offenses include environmental activism and the promotion of Tibet's national culture and language.