Brothers Nguyen Vu Viet and Nguyen Truc Cuong, who were imprisoned for five and four years respectively on 10 September, had their terms cut by the Ho Chi Minh City People's Supreme Court to 32 months on appeal, a court clerk said on Friday.
Their 44-year-old sister, Nguyen Thi Hoa, had her three-year sentence slashed to four months and six days, and was released from custody. Viet, 27, and Cuong, 36, will be released within the next week, he said.
The trio were convicted of providing information by e-mail and telephone to overseas Vietnamese organizations about their uncle, jailed Catholic priest Father Thadeus Nguyen Van Ly, and the religious situation in Vietnam.
Diplomats in Ho Chi Minh City, Vietnam's southern business capital, were refused entry to their appeal trial. The authorities usually ban foreign access to such proceedings involving dissidents.
"This is good news of course, but they should never have been imprisoned in the first place simply for advocating on behalf of a family member. It really was a case of persecution," said a Hanoi-based Western diplomat.
The verdicts came two days after European Union diplomats, in annual human rights talks with the government, demanded "concrete steps and improvements on the ground".
The European Parliament and the US House of Representatives both passed resolutions last week condemning religious repression in Vietnam, prompting an angry reaction from Hanoi over interference in its internal affairs.
"The appeal verdicts could be a nod to foreign pressure. Hopefully it is also recognition by the authorities that these people are not a threat to the government," the diplomat said.
Amnesty International on Wednesday also accused the Vietnamese government of using national security as a pretext to silence cyber-dissidents and stifle freedom of expression on the Internet.
"It really was a case of persecution"
Father Ly, a lifelong critic of Vietnam's religious rights record, was placed under house arrest in March 2001 a month after giving written testimony to the US Commission on International Religious Freedom.
He was sentenced to 15 years in jail in October 2001, but a court reduced the term to 10 years in July this year.