The Office of the National Security Adviser (ONSA) has responded to a letter by former Kaduna State governor, Nasir El-Rufai, seeking clarification on the alleged procurement of approximately 10 kilograms of Thallium Sulphate by the Office of the NSA.
Salient Times reports that El-Rufai raised the concerns in a letter dated January 30, 2026, addressed to the NSA Nuhu Ribadu’s office in the Three Arms Zone, Abuja.
The former governor said he was writing as a concerned citizen to seek reassurance regarding information available to political opposition leaders about the procurement of the toxic chemical from a supplier in Poland.
He noted that thallium salts are highly toxic and tightly controlled substances, making it necessary to confirm critical details for public safety and democratic accountability.
“I am writing as a concerned citizen to seek clarification and reassurance regarding information available to the political opposition leadership about a procurement of approximately 10 kilograms of Thallium Sulphate by the Office of the National Security Adviser (ONSA), reportedly from a supplier in Poland,” El-Rufai stated.
“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,” the former governor wrote.
However, ONSA, in a letter sighted by TheCable, denied the allegation and asked El-Rufai to supply any evidence he has to the DSS for a thorough investigation.
The response, written by OM Adesuyi, a brigadier-general, on behalf of NSA Ribadu, was dated February 13, 2026.
Adesuyi wrote: “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.”
This is coming few days after El-Rufai accused Ribadu of directing the Independent Corrupt Practices Commission (ICPC) to arrest him at the Nnamdi Azikiwe International Airport, Abuja, on Thursday following his return to Nigeria.
According to El-Rufai, while speaking on an Arise TV programme, someone tapped the NSA’s call and revealed to him that the order was from Ribadu.
