Abstract: The study investigated the phenomenon of banking sector frauds in Nigeria, staff involvement and the role of the human resource function in evolving curtailment strategies. It sought, particularly, to determine whether there is a relationship between the amounts of fraud loses in the banking sector and the cadre levels of employees. Using secondary data, estimated losses (EL) to fraud was regressed on number of fraud cases, total amounts and the categories of staff involved. The estimation of the model was based on the ordinary least squares (OLS) method after the necessary pre-testing of the annual time series data using the augmented Dickey-Fuller (ADF) and the Philips-Peron (PP) tests, taken side by side with the related descriptive statistics. The study revealed that the contribution of officers and accountants to fraud losses was the highest compared to the other categorized staff. The study model, considered good for prediction (DW=1.93), revealed that seventy seven percent of frauds are attributable to insiders and about 23% of fraud losses are attributable to non-insider related frauds and forgeries (R2=0.77). Based on the findings, it is recommended, inter alia, that the recruitment process be strengthened through a robust, IT-enabled selection, referencing and personnel lifestyle tracking system. Further, the work environment and job content must be enriched to curtail the opportunity to commit fraud presented when employees are allowed to have wholesome access to assets and information that allow them to both commit and conceal fraud.