The paper investigates the relationship between knowledge (KR) and mindset (MR) on task performance fraud risk assessment (TPFRA) of forensic accountant and auditor in the public sector environment. It also examines the claim that forensic accountants possess higher level of KR, MR and TPFRA than auditors. The study design is cross-sectional. Survey questionnaire is used. The 300 respondents are real professional people (i.e. auditors and accountants in the Nigerian public sector) as true representatives to enhance the generalisation of the outcomes. PLS-SEM and IBM SPSS Statistics 20.0 were used as the primary statistical analysis tools for the study. The results of the present study confirm the positive relationship of KR and MR on TPFRA. Specifically, the results revealed that forensic accountants have higher levels of KR, MR and TPFRA than auditors in the areas of fraud prevention/deterrent, detection and response. Because of the adoption of cross-sectional design in which data are collected at one point of time, there is no time to wait for different follow-up stages or interventions before data analysis. Researchers are encouraged to use longitudinal design to explore interactions between KR, MR and TPFRA. This empirical study has revealed the value of KR and MR (forensic accountant and auditor) as a significant capability requirement in the workplace. Since no nation is immune to fraud and as loss due to fraud is costly, the result of this research will improve the corporate governance and accountability practices among public sector accountants and auditors.