An investigation unit earlier Tuesday launched a raid on Yoon’s security service in an attempt to obtain phone records, the news agency said.
The same unit had previously asked that the suspended president appear to answer questions on Wednesday but were rebuffed by his office, an official told reporters.
Investigators requested Yoon appear at the office at 10 am (9am, Singapore time) for questioning on charges of insurrection and abuse of power, they said.
But the summons “was returned as ‘undelivered'” by the presidential office, they said in a statement.
“The identity of the person who refused to accept it is unknown,” they added.
TURMOIL
South Korea’s Constitutional Court on Monday began proceedings against Yoon and has around six months to determine whether to uphold his impeachment.
A spokeswoman for the court said judges had pencilled in a preliminary hearing on Dec 27, which Yoon is not required to attend.
Fresh elections must be held within two months if his removal is upheld by the Constitutional Court. Prime Minister Han Duck-soo is serving as interim leader in Yoon’s stead.
Yoon was removed by South Korea’s parliament on Saturday over his short-lived attempt to suspend civilian rule, which plunged the country into its worst political turmoil in years.
Vast protests against the ousted leader, with smaller rallies supporting him, have rocked the South Korean capital since his short-lived December 3 martial law decree.
