The Office of the National Security Adviser has asked former Kaduna State governor Nasir El‑Rufai to submit any evidence he possesses regarding the alleged procurement of a toxic chemical to the Department of State Services for a comprehensive investigation, ONSA said in a response to El‑Rufai’s letter.
El‑Rufai wrote to the National Security Adviser, Nuhu Ribadu, in late January 2026, seeking clarification over reports that the Office of the National Security Adviser had procured about 10 kilograms of thallium sulphate, a substance described as highly toxic, from a supplier in Poland.
Thallium sulphate is a colourless and odourless compound that is tightly controlled internationally because of its toxicity. El‑Rufai’s letter asked for details on purpose, quantity, supplier identity and regulatory oversight related to the reported transaction.
In a formal response dated February 13, 2026, signed by Brigadier‑General O.M. Adesuyi on behalf of Ribadu, the Office of the National Security Adviser said it had neither procured nor initiated any process for procuring the material, and said it had no intention of doing so.
The ONSA response confirmed that the matter has been referred to the Department of State Services for a detailed probe and that El‑Rufai “and other parties involved who may possess relevant information” will be contacted by the DSS to provide evidence that could “assist in an in‑depth investigation.”
Officials said that the initial delivery of the ONSA response letter to El‑Rufai’s Abuja residence was delayed when security personnel on duty reportedly declined to accept it, citing the absence of the head of security on Friday.
The letter was eventually delivered on Sunday, and the head of security signed to receive it on behalf of El‑Rufai.
The ONSA directive to submit evidence to the DSS formally places the matter within an investigative framework, signalling that the allegation will be examined by Nigeria’s domestic intelligence service.
By referring the claim to the DSS, ONSA has stated that it is not taking administrative action on the alleged procurement itself but is moving the issue to an investigative agency.
Submitting evidence to the DSS by parties with relevant information may shape the scope and depth of the investigation and inform any subsequent findings or official conclusions.
