The Office of the National Security Adviser (ONSA) has responded to claims by former Kaduna State governor Nasir El-Rufai regarding the alleged procurement of a toxic substance, asking him to provide any evidence he may have to security authorities.
El-Rufai had written to the National Security Adviser, Nuhu Ribadu, alleging that approximately 10 kilograms of thallium sulphate, a highly toxic, colourless and odourless chemical capable of causing death in small amounts, had been sourced from a supplier in Poland.
In its reply, dated February 13, 2026, and signed by Brigadier-General O.M. Adesuyi on behalf of ONSA, the office denied any involvement in such a transaction and confirmed that the matter had been referred to the Department of State Services (DSS) for investigation.
“I have the honour 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 letter said.
The response clarified that ONSA had neither initiated nor carried out any purchase of the chemical.
“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 read.
According to the correspondence, the allegation, which also suggested that details of the supposed transaction were known to opposition figures, has been formally handed over to the DSS for a thorough probe.
“I am further directed to state that the allegation has been formally referred to the Department of State Services for a comprehensive investigation,” the letter stated.
The NSA’s office added that El-Rufai and any other individuals with relevant information would be contacted as part of the 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.”
Sources indicated that an initial attempt to deliver the letter to El-Rufai’s Abuja residence was unsuccessful after security personnel reportedly declined to accept it. It was later delivered on Sunday and received on his behalf.
The exchange comes amid separate claims by El-Rufai that he had access to an intercepted phone conversation involving Ribadu. During an appearance on Arise TV, he alleged that the NSA’s phone had been tapped and that he listened to a conversation in which Ribadu was said to have instructed security operatives to arrest him.
He said during the programme that “someone tapped” the NSA’s phone and that he heard instructions allegedly given to security agencies to take him into custody.