The government's top spokesman expressed concern Monday about the excessive amounts of overtime being put in by officials responsible for dealing with the COVID-19 pandemic, describing working nearly 400 extra hours per month as "very abnormal."

Chief Cabinet Secretary Katsunobu Kato's call for a review of their workload came after figures showed Friday that staff at the Cabinet Secretariat's Office for Novel Coronavirus Disease Control had been in the office for an average of 124 hours outside of their normal work hours in January, with one person clocking 391 hours of overtime.

Yasutoshi Nishimura, the minister in charge of the country's COVID-19 response, has apologized for allowing overtime far above the government's labor guidelines and has vowed to implement reforms to "ease the burden" on his staff.

The Health, Labor and Welfare Ministry sets the threshold for determining overwork as the cause of death or disease at 100 hours of overtime in the preceding month, or an average of 80 hours over the preceding two to six months.

On Friday, Taro Kono, minister in charge of civil service reform, described the situation as "blacker than black."

Nishimura said his staff racked up the long hours in January because of work related to Prime Minister Yoshihide Suga's declaration of a state of emergency in the Tokyo metropolitan area, as well as a revision to the special measures law on the coronavirus.

The Office for Novel Coronavirus Disease Control had 102 members as of the end of January, with none using the option to work from home, according to a written answer from the government in response to a question from lawmaker Kiyoshi Adachi.

Staff members spent an average 104 hours in the office outside of normal work hours in November and 89 hours in December.