The Postal Service inspector general’s office is doing its second review of a controversial surveillance program that allows law-enforcement agencies to intercept suspects’ mail items before they are delivered to record their information.

A previous review that found the Postal Service almost never denies requests for so-called mail covers from outside law-enforcement organizations, saying the agency only rejected about 0.2 percent out of 6,000 in 2013.

Additionally, about 20 percent of the requests from outside law-enforcement agencies were not approved by authorized personnel, and 13 percent were either unjustified or incorrectly documented, according to a report on the findings.

The audit also revealed that USPS did not always process the requests in a timely manner and that law-enforcement agencies regularly failed to return the documents on time after intercepting them.

With the new analysis, auditors plan to determine whether management issues have contributed to the problems, according to an announcement this month from the inspector general’s office.

The watchdog agency said it will also look at the possible impacts of reporting mail-cover statistics to the public. The Postal Service asked the inspector general not to release data on the program in the last report, saying disclosure would reveal “investigative techniques and related information which could compromise ongoing criminal investigations.”

Law-enforcement agencies use the mail covers to investigate criminal activity, including tracking financial fraud and monitoring drug trafficking. USPS authorized about 49,000 requests for the surveillance technique in 2013.

USPS Deputy Inspector General Tammy Whitcomb testified before the House Oversight an Government Reform Committee in November that “mail covers are an important law-enforcement tool, but adequate supervision is critical to ensure the protection of the public.”

USPS management said in a memo responding to the initial review that it agreed with the findings and planned to tighten up its procedures for addressing the concerns, including restricting the approval of mail-cover requests.