The Office of the National Security Adviser (ONSA) has dismissed allegations by former Nasir El-Rufai regarding the purported procurement of thallium sulphate, a highly toxic, colourless and odourless chemical, urging him to provide any supporting evidence to security authorities.
El-Rufai had written to National Security Adviser Nuhu Ribadu claiming that approximately 10 kilograms of thallium sulphate were sourced from a supplier in Poland and that details of the alleged transaction were known to opposition figures.
In a response dated February 13, 2026, signed by Brigadier-General O.M. Adesuyi on behalf of ONSA, the office denied involvement in such a purchase and confirmed that the matter had been referred to the Department of State Services (DSS) for investigation.
“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 stated. It added that El-Rufai and other relevant parties would be contacted to provide evidence to assist the investigation.
Sources said the letter was initially declined at El-Rufai’s Abuja residence but was later delivered and received on Sunday.
The exchange follows separate claims by El-Rufai that he had accessed an alleged intercepted phone conversation of NSA Ribadu, in which he claimed Ribadu instructed security operatives to arrest him—a claim he made during an appearance on Arise TV.
ONSA’s response reiterates its position that the allegations are unfounded and underscores that any credible evidence should be submitted through the appropriate investigative channels.