|By Chinwendu Nwani
The Office of the National Security Adviser (ONSA) has firmly denied allegations that it procured thallium sulphate, a highly toxic chemical compound, and has challenged former Nasir El-Rufai to submit any evidence in his possession to the Department of State Services (DSS) for investigation.
Thallium sulphate is a colourless, odourless and highly poisonous substance capable of killing humans in small doses.
El-Rufai had alleged that ONSA, under the leadership of Nuhu Ribadu, procured about 10 kilograms of the chemical from a supplier in Poland. He demanded urgent clarification over what he described as a suspicious transaction.
In a swift response dated February 13, 2026, ONSA dismissed the claim as unfounded and announced that the matter had been formally referred to the DSS for a comprehensive probe.
The reply, signed by Brigadier-General OM Adesuyi on behalf of the National Security Adviser, acknowledged receipt of El-Rufai’s February 11 correspondence seeking clarification on the alleged procurement.
“I am directed to respectfully convey that ONSA has neither procured nor initiated any process for the purchase of such material, and has no intention of doing so,” the letter stated.
The statement further disclosed that security authorities would invite El-Rufai and any other individuals who claim to have relevant information to assist investigators in establishing the facts.
“The allegation has been formally referred to the Department of State Services for a comprehensive investigation. Your Excellency and other parties involved who may possess relevant information relating to this claim will be duly invited by the Service to provide any evidence that may assist in an in-depth investigation,” the letter added.
According to TheCable, an initial attempt to deliver the official response to El-Rufai’s Abuja residence was unsuccessful after security operatives reportedly declined to receive the document, citing the absence of their head of security and uncertainty about the former governor’s availability.
The letter was eventually delivered on Sunday, with the head of security signing on El-Rufai’s behalf.
The development sets the stage for a formal investigation by the DSS as ONSA insists the allegation is baseless and demands proof to substantiate the claim.
