Joe Biden's security agents in drunken brawl with South Korean taxi driver

President Joe Biden to begin his first trip to Asia as President. Photo / AP

Joe Biden's first trip to Asia as US President has been overshadowed as it emerged that two secret service members had been sent home following a drunken brawl with a South Korean taxi driver.

An agent and an armed physical security specialist were involved in the alcohol-fuelled incident that included a heated argument and the shoving of a taxi driver at 4:20am on Thursday.

Police in Seoul have opened an investigation after the victim and a number of witnesses filed complaints.

Choi Eul-chan, director of the detective division at Yongsan Police Station, told NBC: "We have launched an investigation involving a member of President Biden's security team and a South Korean man."

The Secret Service is conducting its own investigation.

"The Secret Service is aware of an off-duty incident involving two employees which may constitute potential policy violations," spokesman Anthony Guglielmi said. He added that the incident had "no impact" on the President's trip.

Protesters stage a rally to oppose a visit by US President Joe Biden in Seoul, South Korea. Photo / AP

Both Secret Service employees were put on a plane to return to their home duty stations and placed on administrative leave hours before Biden arrived in Seoul to open his visit to South Korea and Japan.

"We have very strict protocols and policies for all employees and we hold ourselves to the highest professional standards," Guglielmi said.

The Secret Service is the 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 to the country by then-president Barack Obama.