Joe Biden’s visit to South Korea and Japan has got off to a bad start with two Secret Service agents set to be sent home after one was accused of drunkenly assaulting a South Korean the day before the president arrived in Seoul, officials said.

Earlier reports said a member of his advance security detail was arrested for allegedly assaulting a South Korean citizen in Seoul.

A US official disputed that the individual was detained or arrested, saying only that he was “investigated” by South Korean officials. The official said the other agent involved in the dispute was not investigated for wrongdoing.

“The Secret Service is aware of an off-duty incident involving two employees which may constitute potential policy violations,” said Anthony Guglielmi, a spokesperson for the agency.

“The individuals will be immediately returned back to their post of duty and placed on administrative leave. There was no impact to the upcoming trip.”

Biden arrived in Seoul on Friday evening, local time.

The team member being investigated, who has not been named, was accused of drunkenly attacking the victim after they got into a dispute over a taxi, media reports said.

The suspect was detained in the early hours of Thursday, a police official in the city’s Yongsan district police told Reuters.

The incident occurred outside the Grand Hyatt hotel, where Biden is expected to stay.

TV Chosun, a South Korean broadcaster that first reported the arrest, said the suspect was in his 30s and had been detained after another guest at the hotel called the police.

Biden began his five-day trip on Friday evening with a tour of a computer chip factory owned by Samsung, which will open a similar plant in Texas, creating 3,000 jobs.

The visit was designed to highlight his plan to increase production of computer chips after a semiconductor shortage last year affected the supply of cars, home appliances and other items.

“These little chips are the key to propelling us into the next era of humanity’s technological development,” Biden said after being met at the plant by South Korea’s new president, Yoon Suk-yeol, and Samsung’s vice-chairman, Lee Jae-yong.

The focus will quickly shift to foreign policy from Saturday, when Biden and Yoon are expected to discuss rising tensions over North Korea’s nuclear and ballistic missile programmes.

Officials in the US in South Korea have warned that the country’s leader, Kim Jong-un, could be preparing to conduct a nuclear test and ballistic missile launch to coincide with Biden’s first visit to the region as president.

On Sunday, Biden will leave for Japan, where he will meet the prime minister, Fumio Kishida, and discuss concerns about China’s growing military activity in the region with the leaders of fellow members of the Quad – an Indo-Pacific strategic alliance that also includes Japan, Australia and India.

The Secret Service is the federal agency that guards the president and the White House.

Secret Service members have periodically been involved in the past in incidents over misbehaviour overseas.

In 2012, 11 Secret Service agents were sent home from Colombia for alleged “misconduct” involving disputes with prostitutes before a visit by then-president Barack Obama.