Judges reversed the verdict on Monday because two of the girls, who had procured several others, had been improperly sentenced as accomplices. They also ordered police to investigate whether senior district officials and businessmen were involved.

Defense lawyers successfully argued the girls were under 18 at the time of the offenses, and had been coerced by principal Sam Duc Xuong, 53, into recruiting their friends.

Presiding judge Nong Duc Toan of the Ha Giang Province People's Court said the district prosecutor had "violated regulations during criminal procedures."

Toan said police were ordered to broaden their investigation, after the girls presented new testimony at trial that they had been forced to have sex with numerous senior district officials and businessmen friendly with Xuong.

Xuong, former principal of the Viet Vinh and Viet Lam High Schools, paid up to nine students aged 13 to 17 to have sex with him beginning in July 2008. He threatened the students with low grades if they did not comply.

Xuong was arrested in September 2009, along with two of the students, Nguyen Thi Thanh Thuy, 18, and Nguyen Thuy Hang, 19. At a closed trial in December, Xuong was sentenced to 10 and a half years in prison. Hang and Thuy received jail terms of six and five years, respectively, for procuring other girls.

Investigators said Xuong had paid the students 1 million dong (56 dollars) for sex. He asked them to procure more students for him, promising to pay 3-4 million dong (168-224 dollars) for virgins.

Police investigated the case based on complaints from parents after they found their children bleeding from the genitals. Xuong argued that he was impotent and could not have committed the offenses.

Deutsche Presse Agentur - February 3, 2010