Opposition lawmakers continued to grill labor ministry officials over a wage data manipulation scandal Friday at the Lower House budget committee, questioning the political neutrality of what the government says is a special independent investigation committee of outside experts.

After the wage data scandal emerged last month, the labor ministry launched the committee under chair Yoshio Higuchi, the president of the Japan Institute for Labour Policy and Training — a think tank affiliated with the ministry.

The committee has conducted interviews with 37 officials and former officials at the Ministry of Health, Labor and Welfare who are suspected of being involved in the scandal. But the ministry later revealed that it was ministry officials, not the committee’s outside experts, who conducted interviews with 25 of the 37 officials.