India's suicide capital Kerala is now exporting the fruit that people here use the most to kill themselves.

The plant bearing the othalanga or cerbera odollam fruit grows wild along the coast in many parts of Kerala, but is also grown as a hedge between home compounds. It’s a potent killer, often used for both suicide and murder.

Worried by the increasing number of othalanga suicides, the state government was recently urged by the Kerala unit of Indian Psychiatric Society and some other organisations to stem its spread.

Taking the lead, a company in Cherthala, a town near Kochi, is procuring large amounts of othalanga each month from locals, paying 40 paise per fruit. It has a local processing yard where workers de-husk the poisonous fruit with their bare hands.

One workers said the fruit are transported to Tamil Nadu and from there exported to manufacturers of bio-insecticides. However, a manager, who gave his name as Sajan, said odalanga goes into making deodorants. Exports are mostly to the US and other Western countries, “besides places like Iraq”, though his company supplies it only to the buyers’ agents, and does not export on its own, he said.

Three years ago, the Journal of Ethnopharmacology in US and international journal New Scientist of UK had published studies by the Laboratory of Analytical Toxicology in La Voulte-sur-Rhône, France, which documented hundreds cases of othalanga-poisoning in Kerala.

One study found that half of Kerala’s plant poisoning deaths, and at least one in 10 of all fatal poisonings, are caused by it. It put the state average for odalanga deaths at almost one a week. Past cases have shown that suicides usually consumed the fruit’s bitter white kernel. About 70 per cent of the dead were women.

For murder, the French study noted that a “few kernels are mixed with food containing plenty of chillies to cover the bitter taste”. Deaths usually occur three to six hours after ingestion, it said.

Othalanga, the study underlined, is a perfect murder weapon as it has a powerful toxin called cerberin, which kills by blocking the calcium ion channels in heart muscles, thus disrupting the heartbeat.

But unlike many toxins, pathologists would not be able to identify othalanga poisoning unless there is physical evidence that the victim had eaten it, said the study. It is “an extremely toxic plant that is relatively unknown to Western doctors, chemists, analysts, and even forensic experts.”