HANOI:A prominent Vietnamese blogger jailed for 12 years for anti-state propaganda has lashed out at the regime from his prison cell, saying his trial had left the country's reputation in tatters.

In a document smuggled out of jail, Nguyen Van Hai -- a founding member of the banned “Free Journalists Club” -- said his trial “was the clearest evidence of the failure of building a democracy in Vietnam”.

The “authoritarian” trial “has destroyed Vietnam's reputation”,    wrote Hai, who is better known by his alias Dieu Cay.

The petition, which Hai tried unsuccessfully to send to senior Vietnamese officials, was carried out of prison by American pro-democracy activist Nguyen Quoc Quan, who was deported from Vietnam last week.

A copy was given to AFP by a US-based dissident group.

“The world needs to know that while the Vietnamese government is attempting to crack down on peaceful dissent, the many imprisoned activists will always find a way to endure,” Quan told AFP by email from California.

“Not even jail cells can confine powerful ideas,” he added.

Hai, whose case has been raised by US President Barack Obama, was sentenced in September along with two other bloggers who received jail terms of 10 years and four years.

In December a court rejected the appeals of Hai and fellow blogger Ta Phong Tan but reduced the four-year sentence of the third defendant by one year.

Rights campaigners say the bloggers are victims of the communist government's efforts to muzzle dissent.

They were convicted of conducting propaganda against the one-party communist state under Article 88 of the criminal code, which rights groups say is one of many “vaguely defined articles” used to prosecute dissidents.

Dozens of peaceful political activists have been jailed since Vietnam began a new crackdown on free expression in late 2009.

So far this year, 36 activists have been convicted under Article 88 in three separate court proceedings.