A construction company on Friday disclosed that has been padding the lodging bills of the decontamination workers involved in decommissioning work related to the Fukushima No. 1 nuclear power plant in Fukushima Prefecture.

Hazama Ando Corp. said an internal probe had found that one of its employees instructed a subcontractor to overcharge the Iwaki and Tamura municipal governments by a combined ¥80 million (around $724,770) and to make it appear that more workers were involved. Receipts for their lodging expenses were found to have been altered.

The central government is helping prefectural and municipal governments decontaminate areas tainted by fallout from the triple core meltdown at the Fukushima No. 1 plant in March 2011.

The contractors secure related work orders from both sectors, but the main contractors customarily shoulder the expenses of the subcontractors, after which the state reimburses them and asks Tokyo Electric Power Co. Holdings Inc. to foot the bill.

Toshiaki Nomura, president of the Tokyo-based construction company, apologized for the incident, which involved the padding of bills related to both decontamination and radiation monitoring in the two cities, which are both around 40 km from the crippled complex.

The company was found to have overcharged Iwaki by an estimated ¥53 million and Tamura by around ¥27 million and to have overstated the number of workers mobilized.

Hazama Ando charged Iwaki ¥7,500 per overnight stay instead of ¥5,000, and stated that around 15,000 workers were involved instead of the actual 11,000.

The Tamura Municipal Government was charged ¥5,500 per person for accommodation, or ¥500 higher than the actual amount, and was told that 10,000 workers were involved rather than 5,600.

Hazama Ando is looking into why an employee instructed a subcontractor to overcharge for accommodations and make it appear that more workers were involved. The employee in question has told the company he had acted "haphazardly."