The Office of the National Security Adviser (ONSA) has formally directed the former Governor of Kaduna State, Mallam Nasir El-Rufai, to submit evidence regarding his allegations of a clandestine procurement of thallium sulphate to the Department of State Services (DSS) for investigation.
Thallium sulphate is a highly toxic, tasteless, and odorless chemical compound capable of causing death in humans even in minute doses.
The directive follows a January 30, 2026, letter addressed to National Security Adviser (NSA) Nuhu Ribadu by El-Rufai. In the correspondence, the former governor alleged that approximately 10 kilograms of the lethal substance had been sourced from a supplier in Poland.
In a swift rebuttal dated February 13, 2026, ONSA denied the claims, stating it has neither procured nor initiated any process to acquire such materials.
The response, authored by Brigadier-General OM Adesuyi on behalf of the NSA and sighted by *TheCable*, confirmed that the matter has been referred to the DSS for a “comprehensive investigation.”
“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 ONSA further noted that El-Rufai, along with any other parties claiming to have information on the purported transaction, would be invited by the DSS to provide evidence to assist in establishing the facts.
“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 statement added.
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The delivery of the ONSA’s response was reportedly marred by initial friction. Sources indicate that a dispatch clerk attempted to deliver the letter to El-Rufai’s Abuja residence on Friday, but was turned away by security operatives who claimed the “head of security” was unavailable.
The letter was eventually received and signed for on Sunday by the residence’s security detail.
This development marks a significant escalation in the public friction between the former governor and the nation’s top security office.
On Friday, during an appearance on Arise Television’s *Prime Time*, El-Rufai leveled further accusations against the NSA, claiming he had accessed an intercepted telephone conversation in which Ribadu allegedly ordered his arrest.
“Someone tapped [Ribadu’s] phone and told us that he gave the order,” El-Rufai told the broadcaster, adding that while such interceptions are technically illegal, “the government does it all the time.”
The DSS investigation is expected to look into both the toxic chemical allegations and the claims of unauthorized surveillance on the National Security Adviser. As of press time, the DSS has not issued a formal statement regarding the timeline for the probe.
