A motorcade of black SUVs was seen leaving the gates of his hillside residence where he had been holed up for weeks behind barbed wire and a small army of personal security.
Mr. Yoon said the “rule of law has completely collapsed” in a video message recorded before he was escorted to the headquarters of an anti-corruption agency.
He said he was complying with the detention warrant to prevent clashes between police and the presidential security service.
However his compliance has not extended as far as actually cooperating with officers, according to the Corruption Investigation Office, which said he was refusing to talk.
It added that he would be held at the Seoul Detention Centre for now.
Mr. Yoon’s lawyers had tried to persuade investigators not to execute the arrest warrant, saying the president would voluntarily appear for questioning, but the agency declined.
Police had been trying to access the president’s official office to detain him but had become engaged in a standoff with Mr. Yoon’s security service.
Hours later, hundreds of officers made it onto the grounds of the property by using ladders to climb over barriers.
Earlier police said they had deployed 3,200 officers to execute the arrest warrant.
One person who collapsed amid the standoff has been transported away from the scene by the fire department, local media said.
The Corruption Investigation Office for High-Ranking Officials and police are jointly investigating whether Mr. Yoon’s martial law declaration on 3 December amounted to an attempted rebellion.
Earlier in the day South Korean investigators arrested the acting chief of the presidential security service, Kim Sung-hoon, for blocking their initial attempt to arrest Mr. Yoon earlier this month.
Mr. Yoon’s presidential security service prevented dozens of investigators from arresting him after a standoff lasted nearly six hours on 3 January.
What happened on 3 December?
Mr. Yoon declared martial law and deployed troops around the National Assembly at the beginning of last month.
It lasted only hours before politicians managed to get through the blockade and voted to lift the measure.
His presidential powers were suspended when the opposition-dominated assembly voted to impeach him on 14 December, accusing him of rebellion.
Mr. Yoon has argued his declaration of martial law was a legitimate act of governance, calling it a warning to the main liberal opposition Democratic Party, which he has described as “despicable pro-North Korean anti-state forces”.
He claimed the party used its legislative majority to impeach top officials and undermine the government’s budget.
Over the past two weeks, thousands of anti- and pro-Yoon protesters have gathered daily in competing rallies near his office in Seoul, in anticipation of his detention.
Source: SkyNews