CAMBODIA'S Appeal Court on Tuesday upheld a 13-year sentence against an American man convicted of having sex with an underage girl.

Myron Maboris, 46, a resident of the US state of Virginia, was originally sentenced to 13 years in prison by the Phnom Penh Municipal Court in June last year.

"Appeal Court Judge Ti Neng ruled against my client, Myron Maboris, for having sex with a 14-year-old girl," defence lawyer Kov Soupha told the Post on Tuesday.

During a hearing on Thursday, Maboris denied the charges, telling the court: "I asked [the girl] only to massage me. I didn't have sex with her."

Teng Maneth, a lawyer with the French child protection NGO Action Pour Les Enfants, welcomed the verdict against Maboris but took issue with the court's decision to dismiss charges against two Cambodian men initially convicted for involvement in the crime.

Police arrested Maboris during an October 2006 raid on his Phnom Penh guesthouse, where they found him with the naked ethnic Vietnamese girl.