By Obinna Uballa
The Office of the National Security Adviser (ONSA) has asked former Kaduna State governor, Nasir El-Rufai, to forward any evidence in his possession regarding the alleged procurement of thallium sulphate to the Department of State Services (DSS) for investigation.
The New Diplomat gathered that the directive followed a letter dated January 30, 2026, in which El-Rufai reportedly raised concerns about the alleged sourcing of the toxic substance from a supplier in Poland.
Thallium sulphate is a highly toxic, colourless and odourless chemical compound capable of causing death even in small doses.
In response to the allegation, the Office of the National Security Adviser, headed by Nuhu Ribadu, denied the claim and requested that the former governor provide any supporting evidence to the DSS to enable a thorough probe.
The reply, dated February 13, 2026, was signed by Brigadier-General O.M. Adesuyi on behalf of the National Security Adviser.
The Cable, an online newspaper, in a report, quoted sources to have further disclosed that an initial attempt to deliver the letter to El-Rufai’s Abuja residence on Friday was unsuccessful. Security operatives on duty reportedly declined to receive the document, informing the dispatch clerk that the head of security was not available and that they were uncertain when the former governor would be present.
The letter was eventually delivered on Sunday, when the head of security signed and acknowledged receipt on El-Rufai’s behalf.
