There have been 26 incidents including theft, conflict of interest and misconduct recorded within the Immigration Service since January 2007.
The Dominion Post reported the figures today. The Labour Department, which immigration comes under, also said there had been cases of improper processing of applications, unauthorised release of personal information and improper cash handling.
The department said all allegations were taking seriously and investigated.
There were four incidents of cash being stolen but no one was caught.
Inappropriate use of email, misuse of the telephone system, accessing records of individuals without a genuine business reason, and using another employee's computer system identity to access or process applications, were the most common examples of improper conduct.
In two cases -- one of misconduct and one of conflict of interest -- staff resigned before investigations were completed, and three staff members were dismissed for failure to follow correct procedures.
National Party immigration spokesman Lockwood Smith was concerned about the culture within the department.
It was previously revealed that between 2004 and 2007 there had been 19 proven cases of theft, bribery and fraud within the Pacific division of the Immigration Service.
As a result, nine people resigned or were fired and three cases were referred to the police.
The Immigration Service is under intense scrutiny with the Auditor-General, the department, State Services Commission and police involved in a variety of inquiries.
The service's problems began in April when it was revealed that Mary Anne Thompson, when she was head of the service, helped three of relatives in Kiribati apply for residence permits. They were approved in dubious circumstances.
Police are looking into allegations about Ms Thompson's qualifications after doubts were raised about a doctorate she claimed to hold from the London School of Economics. Ms Thompson resigned.
