"We've determined that the arrest is impossible," said the Corruption Investigation Office (CIO), which has been investigating Yoon's short-lived martial law declaration.
"Next steps will be decided after review," the CIO said, adding that Yoon's "refusal of the legal process" is "deeply regrettable".
Yoon's supporters, who have been camped out in front of the presidential residence for days, cheered in song and dance as the suspension was announced. "We won," they chanted.
Investigators have until 6 January to arrest Yoon, before the warrant expires. However they can apply for a new warrant and try to detain him again. (BBC)
