The government overstated construction orders data for years, Prime Minister Fumio Kishida admitted Wednesday, in a practice that may have inflated the country's gross domestic product.

The revelation was first reported by the daily Asahi Shimbun, which said the land ministry had been "rewriting" data received monthly from about 12,000 select companies since 2013, at a pace of about 10,000 entries per year.

“It is extremely regrettable, and we need to figure out why it happened and how to prevent a recurrence. That’s a must,” Kishida said during a Lower House Budget Committee session.