The conservative president, seemingly frustrated that his policies were being blocked, declared martial law and ordered troops to surround South Korea‘s National Assembly on 3 December.
The Assembly unanimously overturned the declaration in a matter of hours and impeached Mr Yoon, accusing him of rebellion, on 14 December.
At the same time, anti-corruption authorities and public prosecutors opened separate investigations into the events.
Last Tuesday, a Seoul court issued warrants for Mr Yoon’s detention and for his home to be searched – but enforcing them while he remains inside the residence is complicated.
Ahead of the warrants expiring at midnight on Monday (3pm GMT) thousands of anti-Yoon protesters rallied near the gates of the presidential residence on Sunday, while pro-Yoon groups gathered in a nearby street. They were separated by police barricades.
Some of the demonstrators had gathered overnight, when temperatures fell below -5°C amid a heavy snow warning.
Speaking on stage at the anti-Yoon rally, activist Kim Eun-jeong said: “The presidential security service continues to hide a criminal.”
Nearby, Mr Yoon’s supporters held placards with messages including “We will fight for President Yoon Suk Yeol” and “Stop the Steal” – a phrase popularised by Donald Trump supporters after his 2020 election loss.
At the residence itself, security staff were seen installing barbed wire, possibly in preparation to fend off another arrest attempt.
The president’s lawyers have claimed the arrest warrant is unconstitutional because the CIO, which is leading the criminal investigation, has no authority to investigate insurrection allegations.
Mr Yoon’s defence minister, police chief and several top military commanders have so far been arrested for their roles in the martial law controversy.