An auditor accepts a commission from an insurance company .

Of course.It is a problem about independence.Which standard do you want?

1,
According to the< International Standards on Auditing>,1979-07-01,"International Federation of Accountants," "International Auditing Practices Committee".AU800305

审计人员在执行业务工作中，必须坦白、诚实和恳切。审计必须公正，决不容许偏袒和偏见凌驾于客观性之上。审计人员必须保持公正的态度，在实际上和表现上都不能有任何牵连，这种牵连可以被人认为与正直和客观不能相容（不论其实际影响如何）。

2, Chinese Institute of Certified Public Accountants Code of Ethics

第五条 注册会计师执行审计或其他鉴证业务，应当保持形式上和实质上的独立。