Auditor should watch untiull risk or fraud occur then report same like policeman. Do you agree??

i do not agree , but if the auditor felt bad faith during his audit period through some of documents, he should included in his report. 

A big "NO".

Basically an auditor is expected to evaluate internal control systems as designed and implemented by the company management. Such evaluation is done with the following objectives:

i. To check whether internal controls are operated as desired; or

ii. To check the adequacy of internal control system.

The purpose of evaluation is to make the management aware of the risk of fraud/ wastage of resources in advance. Here, the auditor reports the aforesaid risk like a consultant or advisor listing suitable recommendations to contain the risk before their occurence.

However, once a fraud is occured and audit was carried out then it would be more appropriate to term the audit as an investigation since the purpose is to make a detailed report on how the fraud was taken place. Hence, in case of an investigation the auditor do reports like a policeman.

No. Fraud is not presumed in each and every transaction.Auditors check the control systems and report lapses.Insulating the organisation against perpetration of  frauds is the responsibility of the Management..