The communications ministry will consider taking disciplinary action against Japan Post Service Co. over its delay in delivering a massive number of parcels, officials said Monday.
Any penalties will deal a major blow as the firm struggles to move back into the black.
The Internal Affairs and Communications Ministry will decide whether to order the firm, an arm of the government-owned Japan Post Holdings Co., to improve its operations after hearing what it has to say about the turmoil.
The delivery of some 320,000 parcels was impeded by up to 48 hours between Thursday and Monday after Japan Post's Yu-Pack parcel delivery system was integrated with that of trucking firm Nippon Express Co.
Nippon Express uses different machines for distribution, affecting the smooth handling of parcels, Japan Post Service said. Increased numbers of parcels following the integration also caused troubles.
Officials said parts of the service were still having problems Monday, and it was expected that operations wouldn't return to normal until the middle of the week.
Japan Post Service President Shinichi Nabekura apologized Sunday for the delay.
He said most of the delayed parcels appeared to be coming from postal service centers in Chiba, Aichi and Osaka prefectures, adding that only about 10 delivery centers, including one in Tokyo and Saitama, had been affected.