Le Quoc Quan pictured at his office in Hanoi in September 2012. Pic: AP.

HANOI, Vietnam (AP) — A Vietnamese appeals court has upheld the conviction and 30-month prison sentence against a U.S.-trained lawyer and well-known dissident found guilty of tax evasion in a case that international rights groups say was politically motivated.

The court in Hanoi rejected Le Quoc Quan’s appeal after a half-day trial on Tuesday. His lawyer Ha Huy Son quotes judges as saying they found no new evidence, and that the conviction by the intermediate court was well founded.

Quan was sentenced to 30 months in jail in October.

About 100 people gathered near the courthouse demanding Quan’s release, and police sealed off the area.