Original Framework for Forensic Accounting in Public Sector Procurement Fraud: Evidence from Nigerian Federal Ministries

Public sector procurement fraud in Nigerian federal ministries represents a complex financial crime category requiring specialised forensic accounting frameworks capable of addressing the unique characteristics of government financial management systems, regulatory environments, and political economy dynamics. This doctoral study develops an original forensic accounting framework for investigating procurement fraud in Nigerian federal ministries, drawing on complex empirical evidence from procurement fraud cases investigated between 2017 and 2024. A constructivist grounded theory design was employed, conducting sixty-five semi-structured interviews with forensic accountants, EFCC investigators, Bureau of Public Procurement officials, and federal auditors, supplemented by detailed case analysis of thirty-five procurement fraud prosecutions and archival analysis of 1,200 procurement contract documents from twelve federal ministries. The study theorises the mechanisms by which procurement fraud is constructed, concealed, and detected, developing an original Procurement Fraud Forensic Ontology that categorises fraud typologies, concealment strategies, and documentary evidence signatures specific to the Nigerian federal procurement context. The framework integrates forensic document examination, financial transaction analysis, and contract specification divergence analysis into a unified investigative protocol. Empirical validation demonstrates that the framework generates actionable evidence in eighty-one percent of simulated procurement fraud scenarios. Original contributions include the Procurement Fraud Forensic Ontology, a Nigeria-specific fraud red flag indicator taxonomy, and a structured investigation protocol. Recommendations include national adoption of the framework within the EFCC's forensic accounting division. Keywords: forensic accounting, procurement fraud, federal ministries, Nigeria, grounded theory.