HANOI, Vietnam (AP) — A Vietnamese appeals court on Tuesday 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 quoted judges as saying they found no new evidence, and that the conviction by the intermediate court was well founded.

The lawyer said Quan maintained his innocence throughout the trial.

"I told the court that the case should not be criminalized, but should be resolved through administrative procedures instead." Son said in a telephone interview. "But the court rejected my arguments."

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.

"Le Quoc Quan's innocent. Freedom for the patriot. Down with the trial of injustice," chanted the protesters, many of whom wore T-shirts that read "Freedom for Lawyer Le Quoc Quan".

The United States said Tuesday it was deeply concerned by the Vietnamese government's decision to uphold the conviction.

"The use of tax laws by Vietnamese authorities to imprison government critics for peacefully expressing their political views is disturbing," State Department spokeswoman Jen Psaki said in a statement.

The New York-based Human Rights Watch had called on the court to drop what it called "trumped-up charges of tax evasion" and immediately release the human-rights lawyer.

"Unconditionally releasing Le Quoc Quan would be a welcome step to show the government is sincere about ending the persecution of critics," Brad Adams, Asia director of Human Rights Watch, said in a statement Monday.

Quan, in his early 40s, was detained in 2007 for three months on his return from a U.S. government-funded fellowship in Washington. He was arrested in December 2012.

Western governments and international human-rights groups have criticized Vietnam of jailing people for peacefully expressing their views. Hanoi maintains that only lawbreakers are put behind bars.

Human Rights Watch says the number of people sentenced in political trials has increased every year since 2010 and at least 63 people were imprisoned for peaceful political expression last year.

(Source: http://news.yahoo.com/vietnamese-court-rejects-appeals-dissident-060929875.html)