Health officials in Vietnam have banned a herbal cure for drug addiction and forbidden its inventor from treating patients because of fears that the treatment may have fatal side-effects. The officials said one person had died after taking the remedy, known as heantos. Earlier this year, the United Nations said it would contribute about half-a-million dollars to a project to study the effectiveness of Heantos, after reports it had helped more than 3,000 patients overcome drug withdrawal symptons. Henry Tang reports.

Vietnamese officials say they have prohibited the use of heantos in private clinics in order to protect the public's health. They say that tests of the remedy will continue but only under strict government supervision.

The inventor of heantos, Tran Khuong Dan, has not commented yet on the ban but his fellow researchers dispute the government's claim that one patient has died after taking the cure. They say the individual was already suffering from severe health problems before undergoing treatment.

Heantos, a concoction of tree bark, leaves and various plants found abundantly in Vietnam, has aroused widespread international interest. The United Nations Development Programme is involved in tests both in Vietnam and in the United States and says that initial results have been very good.

Some Vietnamese researchers claim heantos can cure heroin addiction in just three days. Its inventor, a former construction worker, says he was motivated to find a remedy after both his father and brother died as a result of opium addiction.

He says that he himself became an opium addict and then a heroin addict in order to test his own treatment. The Vietnamese government's ban on the free circulation of heantos will inevitably lower expectations that it will become a wonder-cure for drug addiction.