The president of major Japanese housing equipment-maker Lixil Corp. apologized Wednesday for a tasteless joke in which he claimed to have gained weight due to radiation.

"I got bigger because of radiation," Lixil President Kinya Seto said when Environment Minister Koichi Yamamoto asked him about his body during a meeting to discuss what measures should be taken to prevent global warming.

Seto, who used to play basketball and be a boxer, apologized later when reporters asked about the meaning of his comment.

"It was a joke. It was an inappropriate remark," he said. "It was an excuse for me putting on weight."

The Environment Ministry is in charge of decontamination operations in the aftermath of the 2011 Fukushima nuclear crisis.

The comment came days after an education board admitted that a 13-year-old from nuclear disaster-hit Fukushima had been bullied at a school in Yokohama.

The education board said the boy, who was evacuated from Fukushima after the nuclear disaster, had been called "germ" in reference to nuclear contamination, and that he had paid some ¥1.5 million ($13,000) to his classmates to avoid being bullied.