A Korean Air Lines Co. labor union has demanded that a Japanese civil servant accused of assaulting an airport worker in Seoul recently directly apologize and offer compensation to the worker, who is a member of the union.

The union released a statement Friday expressing "serious regret for the unforgivable behavior" by senior Ministry of Health, Labor and Welfare bureaucrat Kosuke Takeda, who has been effectively demoted from his position as the head of the ministry's wage division since the incident. He is accused of committing violence against the worker at Gimpo International Airport last Tuesday.

Calling Takeda, 47, a "labor expert" at the ministry responsible for work-style reform, the statement asked critically why he could treat a worker in another country roughly and with such disdain.

The union also warned that if Takeda does not promptly respond to the demand, it will take action to strip him of his civil servant status.

According to a statement, Takeda tried to board an aircraft in an intoxicated state, and when the union member held him back for the safety of other passengers, he assaulted the worker.

South Korean police earlier said that Takeda was detained Tuesday on suspicion of hitting an airport worker at a boarding gate while under the influence of alcohol.

"He was heavily drunk," police said, adding Takeda admitted the allegations and had made an apology.

Takeda, who was in the country for private business, was later released and has already returned to Japan.

Takeda, however, has disputed the allegations, saying in a Facebook post Wednesday, "In fact, I wasn't drunk. I acted disorderly but didn't hit the airport worker."

He admitted telling the airport worker that he hated South Koreans but said it was because he was angry and there was "no political intention."