The Office of the National Security Adviser (ONSA) has denied claims that it procured thallium sulphate, a highly toxic, colourless, and odourless chemical that can be lethal in small doses.
The denial follows a letter from former Kaduna State Governor Nasir El-Rufai to National Security Adviser Nuhu Ribadu, dated 30 January 2026, in which he claimed opposition sources suggested ONSA had procured about 10 kilograms of thallium sulphate from a supplier in Poland.
Responding on behalf of Mr Ribadu, Brigadier General OM Adesuyi stated that ONSA “has neither procured nor initiated any process for the purchase of such material, and has no intention of doing so.” The letter, first published by TheCable, added that the matter has been referred to the State Security Service (SSS) for a comprehensive investigation, with Mr El-Rufai and other relevant parties expected to provide any evidence they may hold.
In his original letter, El-Rufai described the alleged procurement as a serious public concern, noting thallium salts are “highly toxic and tightly controlled substances.” He sought clarification on six points, including the purpose and end-use of the chemical, supplier identity, regulatory compliance, storage and security arrangements, and any public-health risk assessments. He also copied the correspondence to NAFDAC and the Nigeria Centre for Disease Control (NCDC), which oversee chemical safety and public-health preparedness.
The exchange represents the latest escalation in the longstanding feud between Ribadu and El-Rufai, former allies who rose to prominence under former President Olusegun Obasanjo. Their friendship reportedly fractured in 2011 over political differences during the presidential election, and recent months have seen intensified public confrontations. Last week, El-Rufai accused Ribadu of using anti-corruption agencies to target him, allegations Ribadu has previously dismissed.
The thallium sulphate claim now marks the sharpest point of public tension between the two men, highlighting both safety concerns and political rivalry.
