The sentencing of the monk on Wednesday also came after four activists were ordered to serve prison terms with hard labor on Monday, the day that U.N. envoy Tomas Ojea Quintana arrived in the country to assess the human rights situation.
During his five-day trip, the ruling military further refused him permission to see detained democracy leader Aung San Suu Kyi, as on his two previous visits.
Opposition figures say the latest jailings illustrate the continuation of human rights violations, the lack of an independent judiciary and the junta's disregard for the demands of the United Nations.
A court sentenced monk Gaw Thita to seven years' imprisonment, saying he was guilty of violating immigration laws by taking a trip to Taiwan last year, said Aung Thein, a lawyer known for defending political activists. Gaw Thita was also convicted of unlawful association and failing to declare possession of foreign currency.
The monk had a valid passport for traveling to Taiwan and committed no known immigration violation, the lawyer said. He was jailed in August upon his return from Taiwan with a group of other monks. It is common for monks to take overseas trips for religious reasons.
It was not immediately clear why the monk faced such a harsh penalty, and whether authorities suspected he was involved in political activism. Members of the Buddhist clergy were in the vanguard of mass pro-democracy protests in 2007.
"Myanmar doesn't have an independent judicial system. The courts are passing judgments based on the charges put up by the prosecution rather than on legal facts," said Aung Thein.