Aichi Prefectural Police arrested a construction firm executive on Wednesday for sending a 15-year-old boy to help clean up radioactive waste outside the wrecked Fukushima nuclear plant.

The police said the boy, who is from Kitanagoya, Aichi Prefecture, was sent to Fukushima to cut contaminated leaves and scrape up dirt in the disaster zone last July.

Japan's labor law prohibits people under 18 from working in radioactive areas.

Police arrested Yuji Chiba, 49, who is in charge of the company's labor management and is responsible for the cleanup operations.

The boy started to work at the company in April after graduating from junior high school. He began to clean up the radioactive waste in July, but escaped from the job after working for about five days. He was ordered to lie about his age.

The boy said his former employer had lowered his wages to just ¥3,000 a day and hit him when he did not work hard enough.

Workers cleaning up villages in Fukushima are supposed to receive a special hazard allowance equivalent to about ¥9,000 a day from the government, in addition to their wages.

The March 2011 earthquake and tsunami badly damaged the Fukushima No. 1 plant, sparked a triple nuclear meltdown, forced more than 160,000 residents to flee nearby towns and contaminated water, food and air.

Thousands of workers have been clearing radioactive waste from towns closest to the plant over the past four years.

Japan's traditional subcontracting structure in the construction industry opened up lucrative cleanup contracts in Fukushima to multiple layers of smaller companies that regularly skim workers' pay.