can a self review threat arise when e.g my brother has performed a work (which is a component of a financial statement[FS] ), and i (as a audit partner) checks that FS ?
That’s familiarity threat “the threat that due to a long or close relationship with a client or employer, a professional accountant will be too sympathetic to their interests or too accepting of their work”.
Self-review is “the threat that a professional accountant (e.g. auditor) will not appropriately evaluate the results of a previous judgment made or service performed by the professional accountant, or by another individual within the professional accountant’s firm, on which the accountant will rely when forming a judgment as part of providing a current service (e.g. audit of financial statements)”. In short – arises from reviewing your own work or the work of a colleague.