The Office of the National Security Adviser (ONSA) has denied allegations of the procurement of the toxic substance, thallium sulphate.
Recall that in a letter to National Security Adviser (NSA) Nuhu Ribadu, a former governor of Kaduna State, Nasir El-Rufai, claimed that political opposition leaders obtained information that approximately 10 kilograms of thallium sulphate was imported by ONSA from Poland.
In response to the allegations, a letter was addressed to El-Rufai by Brigadier-General OM Adesuyi, on behalf of the NSA, informing him to submit any evidence to back his claims to the Department of State Services (DSS).
The letter reads as follows: “I have the honor 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.”
More details later.