A Yokohama-based firm has been reprimanded for not having one or more of its workers undergo required health checks after sending them to Fukushima Prefecture for decontamination work in the wake of the 2011 nuclear crisis, labor authorities said on Tuesday.

The Tsurumi Labor Standard Inspection Office issued an order to the firm, which is now undergoing bankruptcy proceedings, in June to take corrective measures for being remiss in its duty to have its workers medically examined.

The inspection office said the firm was a subcontractor for a joint venture led by Tokyo-based general contractor Kajima Corp. that received an order from the Environment Ministry to do work decontaminating soil and houses affected by radioactive fallout from the triple meltdown at Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power plant.

The office is investigating whether the firm, based in Tsurumi Ward, drew up fake health examination reports to make it appear that one or more workers who were dispatched to do decontamination work in Tamura, in Fukushima Prefecture, underwent health checks.

Under the rules of the Ministry of Health, Labor and Welfare, workers involved in decontamination work must undergo medical examinations, including blood and cataract tests and a check for radiation exposure.

Failing to do so is against the law.

In Tamura, workers were responsible for decontaminating the roofs and walls of houses and trying to lower radiation levels in farmland soil, according to the Environment Ministry.