What appeared to be a routine act of distributing health supplements during a Muharram procession in Mumbai turned into a major criminal investigation after police uncovered what they describe as a planned mass-poisoning attempt involving thousands of toxic capsules.

Authorities say the accused, identified as Fayyaz Premji, had allegedly spent nearly 15 days filling empty capsules with zinc phosphide, a highly toxic substance commonly used in rodent-control products, before attempting to hand them out among participants of the Ashura procession in south Mumbai.

The alleged conspiracy came to light only because volunteers and police personnel grew suspicious of the capsules being distributed in the crowd. Investigators now believe the intervention may have prevented a large-scale tragedy.

What happened during the Muharram procession?

The incident happened during the Ashura procession in Mumbai's Byculla-Reay Road area on Friday night.

According to police, Premji was moving through the crowd distributing capsules while claiming they were pain-relief medication or immunity-boosting supplements. The capsules initially attracted little attention as thousands of devotees participated in the religious gathering.

However, volunteers monitoring the procession reportedly became suspicious after examining one of the capsules and noticing an unusual powder inside. They immediately alerted police personnel deployed at the venue.

Officers detained the man on the spot and seized the capsules before more people could consume them.

The seriousness of the case emerged hours later.

Around 4 a.m., a participant identified as Salman Sayed reportedly developed severe stomach pain and vomiting after consuming one of the capsules. Investigators linked the illness to the capsules seized earlier in the night.

Subsequent questioning and preliminary investigation led police to suspect that the capsules contained a dangerous chemical substance rather than medicine.

The accused was formally arrested and later produced before a court, which remanded him to police custody for further interrogation.

Timeline: How the alleged plan happened

Nearly two weeks before the procession

Investigators say the accused allegedly acquired large quantities of zinc phosphide and thousands of empty capsules.

Over the next 15 days, police claim he manually filled the capsules with the toxic substance while staying in Mumbai.

Before Muharram, authorities allege that around 30,000 empty capsules had been procured online as part of the preparation.

What is zinc phosphide and why is it dangerous?

Zinc phosphide is a highly toxic chemical widely used in rat poison and agricultural pest-control products.

Medical experts note that when ingested, the compound reacts with stomach acids and releases phosphine gas, a substance capable of causing severe damage to multiple organs.

Exposure can affect the Heart, Lungs, Liver, Kidneys and Brain.

One of the major concerns associated with zinc phosphide poisoning is the absence of a specific antidote. Treatment typically focuses on emergency medical support and management of symptoms.

Police officials say approximately 14,900 capsules have been seized so far.

Investigators are continuing searches to determine the whereabouts of the remaining capsules and any additional stock of chemicals allegedly connected to the case.

Authorities are also examining procurement records to establish how the materials were sourced and whether anyone else assisted in the operation.