The suspended leader, whose powers have been transferred to an acting president but who remains sitting head of state, also had his mug shot taken and underwent physical examination like his fellow inmates, Shin said.
“The individual cooperated well with the procedures without any particular issues,” Shin said.
According to prison regulations, Yoon will have to change from his normal clothes into a khaki prison uniform, and he will also have been assigned an inmate number.
Prison officials have said his cell includes a small table to use for eating and studying, a small shelf, a sink and a toilet. It also includes a television, but viewing time is strictly restricted.
Inmates are allowed to go out for an hour every day for exercise and shower once a week, but local media have reported that authorities will attempt to prevent him from coming into contact with other inmates.
His personal security detail will accompany him whenever he leaves his cell, reports say.
