The Office of the National Security Adviser (ONSA) has denied allegations that it procured a toxic chemical substance, following claims made by former Kaduna State Governor, Nasir El-Rufai.
El-Rufai had, in a letter addressed to the National Security Adviser (NSA), Nuhu Ribadu, sought clarification over what he described as the alleged procurement of approximately 10 kilograms of Thallium Sulphate by ONSA. According to him, information available to the political opposition leadership indicated that the substance was imported from Poland.
In a formal response published Sunday night per TheCable.ng, the ONSA categorically denied the allegation, stating that it neither procured nor initiated any process for the purchase of the substance.
The letter, signed by Brigadier-General O.M. Adesuyi on behalf of the NSA, acknowledged receipt of El-Rufai’s correspondence dated February 11, 2026. It stated:
“I have the honour to present the compliments of the National Security Adviser and to acknowledge receipt of Your Excellency’s correspondence received on 11 February 2026 requesting clarification regarding the alleged procurement of approximately 10 kilograms of Thallium Sulphate by the Office of the National Security Adviser (ONSA).
“The correspondence further indicated that information concerning the purported procurement is reportedly available to the political opposition leadership. In this regard, 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.”
ONSA further disclosed that the matter has been formally referred to the Department of State Services for a comprehensive investigation.
The letter added that El-Rufai and any other individuals with relevant information would be invited by the security service to provide evidence that could assist in establishing the facts.
“I am further directed to state that 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, establishing the facts and ensuring due diligence,” the letter read.
ONSA concluded by reaffirming the NSA’s regards and reiterating its commitment to due process.
The development comes amid heightened political tensions, as security-related claims continue to generate debate within the nation’s political landscape.
A Security & Defence Analyst/Conflict,
Group Captain Sadeeq Garba Shehu (rtd), had in an article circulating on social media written on the deadly chemical:
A breaking report by Daily Trust has injected an unusually sensitive subject into Nigeria’s public space: a formal letter by Nasir El-Rufai asking the National Security Adviser, Nuhu Ribadu, to clarify reports that the Office of the National Security Adviser allegedly imported thallium sulphate—one of the most dangerous toxic substances known to science.
This is not an ordinary procurement query. It sits at the fault line where toxicology, intelligence history, law, and public trust intersect.
WHY THALLIUM SULPHATE IS NOT “just another chemical”
Historically, thallium sulphate mattered to intelligence services not because it was exotic, but because it was perfectly stealthy, it ticks all the boxes for a weapon of mischief:
a. Colourless, tasteless, odourless
b. Delayed symptoms (often days or weeks later)
c. Once legally sold as rat poison
d. Extremely difficult to diagnose before modern forensic science
These traits placed it squarely in the Cold War catalogue of deniable poisons—tools associated with clandestine coercion, silent elimination, or intimidation, long before forensic toxicology caught up.
That era is over.
Today, thallium is:
a. Easily traceable through hair, nails, bone and tissue
b. Globally restricted because of its lethality
c. Legally indefensible outside narrow, declared laboratory research.
Which is why its mere mention now triggers alarm bells far beyond public health.
POISONS AS INTELLIGENCE & SECURITY PROBLEM
Modern intelligence doctrine has largely abandoned poisons because they are strategically disastrous:
a. They leave forensic trails
b. They create diplomatic explosions
c. They undermine state legitimacy
d. They collapse plausible deniability
In short, poisons don’t stay secret—they boomerang.
This is precisely why many countries moved decades ago to ban or tightly control thallium salts: not only to protect citizens, but to close a covert-action loophole that embarrassed governments and destabilised trust.
WHY EL-RUFAI ’s QUESTIONS ARE LEGITIMATE IN ANY DEMOCRACY
Strip away politics and personalities, and what remains are standard national-security accountability questions:
▪︎What is the intended end-use of a banned toxic substance?
▪︎Was it imported under proper chemical or defence permits?
▪︎How is it stored, secured, and overseen?
▪︎What role do public-health and environmental regulators play?
▪︎Were the regulatory agencies informed?
Has a risk assessment been conducted?
These are not hostile questions. They are the minimum questions any democratic society must ask when extreme-risk materials are involved.
THE WIDER IRONY
This controversy unfolds against the backdrop of an even more troubling claim attributed to El-Rufai earlier—that the NSA’s phone was tapped, without judicial warrant, to obtain evidence of an alleged arrest order.
Taken together, the optics are grim:
▪︎Allegations of unauthorised surveillance of citizens phones by ONSA without warrant
▪︎Allegations of unlawful counter surveillance of NSA phones by private citizens (Two wrongs)
▪︎Allegations of importation of a lethal poison
▪︎Deepening public distrust of security institutions
None of this strengthens national security. All of it weakens it.
THE REAL NATIONAL-SECURITY ISSUE
The issue is not whether Nigeria’s security services ever need dangerous materials for legitimate purposes.
The issue is process, transparency, legality, and trust.
Modern national security is not just about secrecy; it is about credible oversight. When secrecy expands faster than accountability, legitimacy erodes—and legitimacy is the ultimate force multiplier.
BOTTOM LINE
Thallium sulphate is not merely a toxic chemical.
It is a historical symbol of an era when states believed secrecy alone justified everything.
That era ended—not because states became kinder, but because law, forensics, and public accountability caught up.
If Nigerian security and intelligence wish to project themselves and the government they serve as a serious, law-bound democracy, then clear, factual, and prompt clarification is not optional. Even the most innocuous issue if hidden by security agencies when they are unearthed by citizens with long shovels, the security agencies and government itself have lost public trust.
