A panel of experts at Japan's transport ministry has started reviewing the country's auto emissions tests following the revelation that Volkswagen equipped its cars with software to cheat on tests.
Experts in automotive engineering and other areas held their first meeting on Wednesday, public broadcaster NHK reported on Thursday.
Nine firms that sell diesel vehicles in Japan have reported to transport ministry officials that they are not engaged in irregular activities.
The officials added that the government will conduct sample tests to confirm this.
The ministry is considering the introduction of additional on-the-road emissions tests.
The experts plan to draw up an interim report on possible challenges early next year.