Japan’s Ministry of Internal Affairs and Communications ordered Rakuten Mobile to detail corrective measures it will take to address delays in disclosing a data breach to the government, Jiji Press reported.

The ministry stated the company failed to report the breach within 30 days and issued an administrative guidance as Rakuten was obliged to immediately report the incident to authorities, the news agency wrote.

Rakuten took nearly four months to report the breach.

Jiji Press explained the case related to a leak of personal information including call histories of about 7,000 Rakuten Mobile customers earlier this year.

Rakuten is the smallest mobile player in Japan by subscriptions, with almost 9 million at end-June.