Attorney General Paula Dow's action comes after The Star-Ledger of Newark reported last month 90,423 complaints were filed between 2000 to 2008. However, only 86,925 cases were disposed of because of inaccurate record keeping.
The problem occurs when unresolved internal affairs complaints are not added into the next year's report.
State American Civil Liberties Union director Deborah Jacobs says she hopes a review of how the information is collected will lead to a broader review of the internal affairs policy.
The ACLU has pressed a federal investigation of the Newark Police Department.