LUCKNOW A Varanasi-based businessman was allegedly poisoned with thallium, a rare and highly toxic substance, prompting the police to register an attempt to murder case in an incident reminiscent of the slow-poisoning plot in the recently released Hindi movie, Dhurandhar: The Revenge.
The victim has been identified as businessman Sandeep Singh (41), a former Samajwadi Party Chhatra Sabha national general secretary, an officer said.
“A first information report (FIR) was lodged under BNS Section 109(1) (attempt to murder) at the Kotwali police station against unknown persons in Varanasi on Wednesday night based on the complaint by Khushboo Singh, wife of Sandeep Singh,” Kotwali SHO Dayashankar Singh said.
The SHO added that police are probing whether the suspected poison was administered during travel, hospitalisation, business meetings or through food consumed outside the home.
Singh, who runs two transport firms linked to road construction logistics, is currently undergoing treatment at his Lucknow residence under medical supervision, his family members said.
The case has triggered concern due to the nature of the toxin, which is rare, difficult to detect and often mimics neurological disorders in its early stages.
In her complaint, the victim’s wife has alleged that an unidentified person might have administered the poison with an intent to kill.
{{/usCountry}}In her complaint, the victim’s wife has alleged that an unidentified person might have administered the poison with an intent to kill.
{{/usCountry}}The family grew suspicious after doctors at a Mumbai hospital reportedly detected traces of thallium in his blood.
According to the FIR, Singh first fell ill in late February 2025 while in Gurugram, where he had accompanied an acquaintance undergoing treatment. Initial symptoms—fever, tingling in the legs, body pain and vomiting—progressively worsened into a severe neurological condition.
He was first admitted to Medanta Hospital and later shifted to Max Super Speciality Hospital, where doctors reportedly suspected Guillain–Barré syndrome (GBS). As his condition deteriorated, he was airlifted to PD Hinduja Hospital in Mumbai, where toxicology tests confirmed the presence of thallium in his bloodstream, the FIR said.
Sandeep Singh’s brother, Ajit Singh, said: “We first lodged a zero FIR at Mahim police station in Mumbai on March 30, 2025, soon after doctors suspected poisoning.
However, the case file was sent back to Mumbai nearly five months later, resulting in a delay in formal registration and investigation.”
“The FIR was finally registered on Wednesday,” he added.
Medical literature describes thallium as the “poisoner’s poison” because it is colourless, odourless and tasteless, making it extremely difficult to detect if mixed with food or drink.
The investigation is underway, said police.