A special investigative panel of Japan's health and labor ministry says there was no systematic cover-up in the ministry's flawed statistics scandal.
The ministry set up the panel of outside experts in January to probe illegalities linked to its monthly survey on wages and working hours.
The panel concluded the ministry had no intention to cover up the flaws. But it was forced to reexamine the matter after its work was criticized as too hasty.
The panel compiled a report on Wednesday saying all former heads of the ministry's statistics division since 2004, when the flaws began, denied knowing the data were skewed.
As for their subordinate section chiefs, the panel learned that an individual who assumed the post in 2013 was the first to notice the flaws. But the person did not make corrections, and deleted references to the flaws from a statistics survey manual.
The head of the office in charge of the survey learned of the flaws from a predecessor, and began correcting the data last year. But the person neither publicized the correction procedure nor reported it to his superiors.
The panel report clears both the section chief and the office head by pointing out it cannot acknowledge that an intentional cover-up took place.
Meanwhile, opposition lawmakers are demanding to know whether the prime minister's office played a role in the change of the survey method.
The panel report denies that the method change was aimed at making it seem that wages had gone up. It says the move was aimed at making the data more understandable for users, and describes it as statistically rational.
Health and labor minister Takumi Nemoto said he will read the report thoroughly, and vowed to spearhead efforts to establish governance in his ministry to correct administration of statistics from the root. He said he takes the harsh criticism seriously.
Seiji Osaka of the Constitutional Democratic Party is the top opposition director of the Lower House Budget Committee. He said the report's conclusion that no cover-up took place when in fact one did makes the report meaningless. He dismissed what he described as the ministry's interpretation of facts for its own convenience.