At least 19 children have died in India after consuming cough syrup containing diethylene glycol, a deadly industrial solvent.
The contaminated syrup was manufactured and sold in India under the name Coldrif.
As Coldrif was pulled from the shelves, authorities arrested the owner of its manufacturer and shut down a facility in Chennai.
Gujarat State later recalled two other cough syrups, Respifresh TR and Relife, that had also tested positive for diethylene glycol.
Commonly used in anti-freeze and brake fluid, even tiny amounts of the chemical can cause renal failure and brain damage.
A spokesperson from the World Health Organisation told the ABC it "has not received any official information as to the source of the diethylene glycol contamination or if contaminated pharmaceutical material has been identified".
Testing concerns
The mass poisoning is only the latest of a familiar pattern in India.
The country has witnessed hundreds of children die in multiple cough syrup poisonings over decades, predominantly in poor rural communities.
Prashant Reddy, lawyer and author of The Truth Pill: The Myth of Drug Regulation in India, said "it was only a matter of time before we saw another tragedy".
Regulation of pharmaceutical production in India was heightened after the deaths of more than 300 children in Gambia, Uzbekistan and Cameroon were linked to Indian syrups in 2022.
However, experts say the laws mandating testing for raw materials and final products are not enforced and that regulators focus their attention on the export market, frequently failing to test domestic products.
"It is a combination of both corruption and incompetence," Mr Reddy said.
"The question is, why was this not caught earlier? The law mandates annual inspections of each facility."
The WHO was assured by India's Central Drugs Standard Control Organisation (CDSCO) that all three contaminated syrups had been recalled and none had been exported from India.
But the WHO has warned poisoned cough syrups may have been exported from India via unregulated channels.
Turning a blind eye
Mr Reddy said authorities continued to ignore issues in cough syrup quality, after successive years of CDSCO testing found more than a hundred failures in syrups sold across India.
"These days, tragedies like this in India get wiped out of the front page quite quickly, and the government doesn't get to the root of the matter because the government's first instinct generally is to protect itself first, and then the pharmaceutical company," Mr Reddy said.
"Somewhere in between, the truth disappears."
India's pharmaceutical industry is valued at $76 billion and exports account for more than half of its value.
Veteran Indian journalist Barkha Dutt gave a blunt assessment of the latest poisoning.
"This should not be thought of as an accident," she told ABC's The World program.
"All of these cough syrup bottles contain a toxin that is well beyond ... the permissible level. Heads should roll."
Most of the deaths took place in a small town in Madhya Pradesh's Chhindwara district.
After the arrest of a paediatrician who prescribed the Coldrif medicine, doctors across India went on strike to demand manufacturers and regulators be held accountable.
Antifreeze in cough syrup
When Coldrif cough syrup was tested after the poisonings began, the presence of the chemical toxic diethylene glycol was recorded in quantities nearly 500 times the permissible limit.
The active ingredient in antifreeze should not be present in cough syrup in any quantity, nor is it used in its manufacturing.
Prashant Reddy said it may have contaminated the syrups via poor quality supplies of propylene glycol, a solvent used in medicine production.
"This is a known issue; they are supposed to be testing propylene glycol before they use it, the law mandates such testing," he said.
"But it is very evident that a lot of pharmaceutical companies in India, especially smaller ones, aren't conducting this testing."
In a public statement after the poisonings, India's drugs controller General Rajeev Singh Raghuvanshi did not specify how many pharmaceutical manufacturers had been inspected but confirmed at least some were failing to test their products.
Despite a string of tragedies in Indian oral syrup manufacturing spanning back to at least 1973, Mr Reddy said there had been only one serious commission of inquiry into the issue.
"In this particular case, going by the reportage in the Indian press, it's evident that this manufacturer should have been shut down long ago, it was running out of a really ramshackle facility," he said.
The Tamil Nadu Drugs Control Department, which is responsible for regulating the manufacturer of Coldrif, did not respond to the ABC's questions in time for publication.
The Indian Express labelled the site of the Chennai manufacturer "stark and unhygienic" with "stained concrete floors" and the "reek of hurried abandonment".
