Nasir el-Rufai, the former governor of Kaduna State, has formally requested clarification from Nuhu Ribadu, the National Security Adviser (NSA), regarding an alleged procurement of approximately 10 kilograms of thallium sulphate by the Office of the National Security Adviser (ONSA). In a letter dated January 30, el-Rufai stated he was acting as a concerned citizen to seek reassurance about information available to political opposition leadership concerning the reported acquisition of the highly toxic substance, reportedly sourced from a supplier in Poland.

El-Rufai underscored the extreme danger of thallium salts, describing them as "highly toxic and tightly controlled substances." He emphasized the importance of confirming specific details in the interest of public safety and democratic accountability. His detailed inquiry included requests for the intended purpose and end-use of the imported thallium sulphate, the identity of the supplier, and whether the material was imported under an existing chemical or defense permit. He also sought information on the total quantity and specific form or concentration procured, as well as the storage and security arrangements upon arrival.

Furthermore, the former governor requested clarification on the regulatory oversight and coordination with relevant public-health and environmental agencies, specifically mentioning the National Agency for Food and Drug Administration and Control (NAFDAC) and the Nigeria Centre for Disease Control (NCDC). He also asked whether any public-health risk assessments or hazard-mitigation plans had been developed, considering the compound's extreme toxicity. El-Rufai explicitly stated his inquiry was made "in good faith, solely to ensure that due processes, safety standards, and transparency are observed," believing that "public confidence in the integrity of national institutions is strengthened when potential risks are openly addressed and managed." Copies of the correspondence were sent to the Director-General of NAFDAC, the Director-General of NCDC, and the national chairmen of the African Democratic Congress (ADC) and the Peoples Democratic Party (PDP).

The allegations have sparked mixed reactions, with the NSA's office yet to issue a public response. While members of the ruling All Progressives Congress (APC) have reportedly rejected the claim, opposition figures have called for an immediate probe. Human rights lawyer, Deji Adeyanju, dismissed el-Rufai's allegations, describing the former governor as an "unrepentant liar." Adeyanju acknowledged the possibility of ONSA importing toxic materials but stated that, given the source, he considered the claim a lie and propaganda, referencing el-Rufai's past controversial statements.

Adding another layer to the controversy, el-Rufai recently alleged that he had accessed an intercepted telephone conversation involving Ribadu. Speaking on an Arise Television program, el-Rufai claimed that "someone tapped" Ribadu’s phone and that he heard the NSA allegedly directing security operatives to arrest him. While acknowledging the illegality of phone tapping, el-Rufai claimed such practices are routinely carried out by the government. The situation continues to unfold as the public awaits a formal response from the Office of the National Security Adviser regarding the serious allegations.