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..

In case that fraud is perpetrated or an error occured and was not timely detected and corrected, the auditor has failed his mission. The role of the auditor is more preventive than detective.