The Office of the National Security Adviser (ONSA) has responded to Malam Nasir El-Rufai, former governor of Kaduna State, who earlier sought clarification over the alleged importation of a toxic substance from Poland.

In a letter to Nuhu Ribadu, National Security Adviser, El-Rufai had said information available to the political opposition leadership showed that there was procurement of approximately 10 kilograms of Thallium Sulphate by ONSA.

"Given that thallium salts are highly toxic and tightly controlled substances, I believe it is important for public safety, democratic accountability and for maintaining public trust to confirm the following details:

"1. The intended purpose and end-use of the imported thallium sulphate.

"2. The supplier identity and whether the material was imported under an existing chemical or defence permit.

"3. The total quantity and specific form or concentration being procured or already procured.

"4. The storage and security arrangements for the maserial upon arrival

"5. The regulatory oversight and coordination in place with NAFDAC, NCDC, and relevant public-health and environmental agencies.

"6. Whether any public-health risk assessments or hazard-mitigation plans have been developed, given the compound’s extreme toxicity.

"I want to stress that this inquiry is made in good faith, solely to ensure that due processes, safety standards, and transparency are observed. Public confidence in the integrity of national institutions is strengthened when potential risks are openly addressed and managed.”

But in a response published by TheCable on Sunday night, ONSA replied him denying the allegation and asking him to supply any evidence he has to the DSS for a thorough investigation.

The letter written by Brigadier-General OM Adesuyi, on behalf of the NSA, read, “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.

“However, 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.

“Please accept the assurances of the esteemed regards of the National Security Adviser.”

El-Rufai is yet to publicly react to the development but the online publication said the letter, which was initially rejected, was eventually delivered on Sunday.

A security aide of the former governor was said to have received it on his behalf. (Text, excluding headline: Daily Trust)

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