Roman Zmajkovie (R) stands in court next to an intepreter in Hanoi on Tuesday. Photo acquired by VnExpress

Roman Zmajkovie, 33, was charged with "Having sexual intercourse with children," a crime punishable by imprisonment of up to 15 years.

He should be deported after serving his term, the court said.

According to the indictment, Zmajkovie entered the country on a tourist visa late last year, but did not leave when it expired and continued to stay on.

He took advantage of knowing a little Vietnamese and went to Thien Quang Lake in Hai Ba Trung District to make the acquaintance of the boy.

He promised him money in exchange for a sexual relationship, and gave him VND300,000 ($12.8) after having sex for the first time early this year and VND500,000 the next time.

The police caught him red-handed May 4 when he was having sex with the boy at a hotel in Hoan Kiem District.

The boy refused to undergo a medical examination or treatment but asked Zmajkovie for VND105 million ($4,489) in compensation for his physical and mental damage.

The United Nations had said last year that one in four children in Vietnam is a victim of abuse and at least 1,300 cases of sexual violence against children are reported each year.

While official statistics are unavailable, the U.N. estimates the true numbers are consistently alarming.