The Office of the National Security Adviser (ONSA) has asked former Kaduna governor Nasir El-Rufai to submit evidence supporting his allegation that it procured a highly toxic substance.
In a formal response, ONSA, led by Nuhu Ribadu, directed El-Rufai to provide any proof regarding the alleged purchase of thallium sulphate to the Department of State Services (DSS) for investigation.
Thallium sulphate is a colourless, odourless chemical compound capable of killing in small doses.
In a letter dated January 30, 2026, and addressed to Ribadu, El-Rufai claimed that approximately 10 kilograms of the toxic substance had been sourced from a supplier in Poland. He further alleged that details of the procurement were known within opposition political circles.
However, ONSA firmly denied the claim.
In a February 13, 2026 response signed by Brigadier-General OM Adesuyi on behalf of the NSA, the office stated it had neither procured nor initiated any process to purchase the substance, and had no intention of doing so.
ONSA confirmed that the allegation has been formally referred to the DSS for a comprehensive probe.
The letter stated that El-Rufai and any other parties with relevant information would be invited to provide evidence to assist in establishing the facts and ensuring due diligence.
A copy of the response sent to El-Rufai’s Abuja residence was initially rejected by security operatives on Friday. The dispatch clerk was reportedly informed that the head of security was not available and that they were unsure when the former governor would be present.
The letter was eventually delivered on Sunday and received by the head of security on El-Rufai’s behalf.
On Friday, El-Rufai also claimed he had listened to an intercepted telephone conversation allegedly involving Ribadu.
Speaking on Prime Time on Arise TV, he alleged that someone had tapped the NSA’s phone and that he heard Ribadu directing security operatives to arrest him.
ONSA has not publicly responded to that specific claim.
