Child sex tourism is not mentioned specifically in Vietnamese legislation, but there are fears that it could be growing as the nation makes big advances in attracting holiday makers - and as Vietnamese themselves move more and more around the country.

Legal expert Le Thi Hoa from the Justice Ministry's Department of Criminal and Administrative Laws said that existing regulations in the penal code, child care, protection and education, anti-human trafficking and prostitution seemed to cover this kind of crime.

However, she said there was a need for a legal framework directly targeting the crimes.

Child sex tourism is described as the sexual exploitation of children by a person or persons who have sexual contact with children.

Offenders can be domestic travellers or international tourists. According to Vietnam travel agency, child sex tourism often involves the use of accommodation, transportation and other tourism-related services that facilitate contact with children and enable the perpetrator to remain fairly inconspicuous.

Figures from the Public Security Ministry show that in the last three years, more than 4,350 crimes were recorded as being committed against children.

They involved child abuse, child labour, domestic violence, but 61 per cent involved sexual crimes against children.

Senior Lieutenant-Colonel Nguyen Van Trang from the ministry's Criminal Police Department said that crimes against children were increasing as family members including fathers, stepfathers and brothers became involved.

Only a few cases of sexual crimes against children committed by travelling offenders were reported each year, most were committed by foreign tourists, businesspeople and even English teachers. This may be the tip of the iceberg, authorities say.

Trang mentioned a child rape case in southern Vung Tau City in 2006. Gary Glitter, an English rock singer, was arrested for having intercourse and committing indecent acts against girls in the city, one as young as 12. The singer was sentenced to three years' imprisonment by Ba Ria-Vung Tau Province Court.

Trang said school dropouts and street children, especially those in big tourist cities such as Vung Tau, Nha Trang, Ha Noi and Hai Phong were vulnerable to sex offenders.

However,he said that data on child sex crimes was not properly updated or analysed, especially offences committed by travelling offenders - either Vietnamese or foreigners.

"Due to fear of stigmatisation and negative impacts on a victim's future, their family are reluctant to report cases, making it hard to detect or investigate," Trang said.

Lindsay Buckingham, a legal consultant for the United Nations Office on Drug and Crime (UNODC), said Viet Nam's legal framework provided protection for children from sexual exploitation and criminal conduct and upheld their rights as victims and witnesses.

"However, when compared with international standards, there are gaps in the current domestic legal framework relevant to child sex tourism," she said.

Buckingham said when a country cracked down on child sexual exploitation, foreign offenders were likely to move their activities to neighbouring countries with looser laws. This called for a regional approach to the problem.

In a just completed two-day workshop titled A Legal Framework for Combatting Child Sex Tourism held by the Ministry of Justice and UNODC, the first discussion on child sex tourism in Viet Nam was introduced.

It is part of a four-year project called Project Childhood, introduced last year by UNODC, Interpol and World Vision in Cambodia, Laos, Thailand and Viet Nam, to combat the sexual exploitation of children, particularly in the tourism sector.

Project co-ordinator Margaret Akullo said legal responses against child sex offenders must become a more important element in reversing child trafficking, abuse and sexual exploitation.

UNODC will provide technical assistance to law enforcement agencies in conducting investigations, Interpol will bring together international, national and regional investigative resources to target travelling child sex offenders.

The US$7.5 million project has been funded by the Australian Agency for International Development (AusAID).