JAKARTA • The wife of a Canadian man, whose acquittal for child sex abuse at an elite Indonesian school has been overturned, has tearfully vowed to fight against the "travesty of justice" and launch a new appeal.

She also described the decision to reinstate the conviction of her husband, school administrator Neil Bantleman, as "inhumane, ridiculous and absurd", hours after he was sent back to jail in Jakarta.

His co-defendant, Ferdinand Tjiong, an Indonesian teaching assistant at the elite Jakarta Intercultural School (JIS), has also returned to prison after the Supreme Court threw out the men's acquittals and increased their sentences from 10 to 11 years.

The case has been criticised as fraught with irregularities and based on weak evidence. After news of the latest decision emerged on Thursday, Canada, Britain and the United States expressed shock and warned it raises questions about the rule of law in Indonesia.

The two men have always maintained their innocence, and have received strong support from the expatriate community and the school, which is a favourite with foreigners and wealthy Indonesians.

Bantleman's wife, Tracy, broke down in tears at a press conference in Jakarta on Friday, as she angrily criticised the decision to send her husband and Tjiong back to prison.

"Our husbands are innocent," she said, sitting alongside Tjiong's wife, Sisca. "This is a travesty of justice and the world knows it... We will fight for justice as long as it takes."

She said the men planned to appeal against the Supreme Court's decision by applying for a judicial review. The pair were originally jailed in April last year for abusing young children at JIS. They were released several months later after winning an appeal in the High Court, but prosecutors then successfully challenged this decision at the Supreme Court.

AGENCE FRANCE-PRESSE