Two former public officials who were in charge of drug regulation offices were arrested as part of the high-profile case investigating batches of contaminated medical-use fentanyl that caused the death of over 90 patients and affected 41 others.
Nélida Bisio, who led Argentine food and drug regulator ANMAT between late 2023 and early 2026, and former head of the National Institute of Medicines Gabriela Mantecón Fumadó, were arrested by the Federal Police on Tuesday under orders of La Plata Judge Ernesto Kreplak.
Kreplak is expected to question Bisio and Mantecón Fumadó on Wednesday.
The arrests of Bisio and Mantecón Fumadó were requested by prosecutors María Laura Roteta and Sergio Rodríguez, who argued that the former public officials were responsible for covering up the history of noncompliance and irregularities regarding good manufacturing practices of the laboratories that produced the drug.
The prosecutors said that there was a “state-sponsored cover-up that allowed the laboratories to continue their production activities under appalling quality conditions,” leading to the contamination of the batches of the synthetic opioid, according to a statement from the General Prosecutors’ Office.
“The prosecution’s theory is that the former officials were responsible for the production, distribution, and supply of the contaminated fentanyl,” the office affirmed in its statement.
The case
News about the death of patients that had died after being administered contaminated fentanyl for treatment while hospitalized broke in May 2025. The batches were produced in late 2024, and the first victim died in February 2025.
The death toll increased significantly in April 2025, leading to the suspicion that they had been killed by infections caused by bacteria present in medical-use fentanyl.
The fentanyl, produced by labs HLB Pharma Group and Laboratorios Ramallo (owned by HLB Pharma), was produced in late 2024 and distributed in health centers in the provinces of Buenos Aires, Santa Fe, Córdoba, Formosa, and Buenos Aires city.
Patients that received the opioid for pain relief or anesthesia were infected with two antibiotic-resistant bacteria that caused them pneumonia: Klebsiella pneumoniae MBL and Ralstonia Pickettii.
The case began after food and drug regulator ANMAT filed a criminal complaint and ordered a halt to the use and distribution of two batches of medical-use fentanyl. ANMAT had received a report from a private clinic in La Plata of an outbreak of unusual in-hospital infections and deaths, which were traced back to the use of those batches of fentanyl in the affected patients.
Authorities seized the remaining contaminated batches and arrested the owner of HLB Pharma Group and nine other executives. Kreplak is investigating over 20 suspects and probing regulatory oversight failures.
So far, 96 deaths have been confirmed to be linked to the contaminated batches, but a further 70 deaths remain under investigation.
How the investigation is unfolding
The prosecutors requested Bisio and Mantecón Fumadó be charged with “poisoning, adulterating, or falsifying” public-use medicine “in a manner that is hazardous to health” as well as with the death or injury of people as a result of the adulteration of medicine. If found guilty of the latter crime, they could be sentenced to 10 to 25 years in prison.
According to the prosecutors’ office statement, “it has been proven” that Bisio and Mantecón Fumadó “knew about the high risk created by the conditions in which the labs produced the medication, and that they could lead to deaths and injuries.”
Despite that knowledge, “they did not activate as urgently as needed efficient prevention mechanisms to avoid or stop the distribution of those products.”
Over late 2024 and early 2025 ANMAT carried out an inspection in Laboratorios Ramallo during which they detected quality violations and irregularities, prompting the agency and the National Institute of Medicines to alert of potential health risks and warn the company.
The inspection happened right before the batches of contaminated fentanyl were produced. In February, ANMAT ordered Laboratorios Ramallo and HLB Pharma to halt production altogether, but the contaminated fentanyl batches were still distributed and continued to be used for months unbeknownst to the risks. The first alert of a patient killed by them would come in May, but many others had died by then.
Ariel García Furfaro, owner of HLB Pharma and Laboratorios Ramallo, as well as his brothers, Damián and Diego and seven other people linked to the company, were arrested in August as part of the ongoing case.
