Choi Soon-Sil, a long-time friend of the president, has repeatedly snubbed a parliamentary committee probing a corruption scandal that triggered Park's impeachment earlier this month.
Currently on trial for extortion and abuse of power, Choi had ignored several summons to attend the committee’s hearings in the National Assembly -- prompting the lawmakers to come to her.
A special, televised hearing was convened in the detention centre where Choi is being held on the outskirts of Seoul, but lawmakers were left with little to do but vent their frustrations after she refused to leave her cell.
Two former top presidential aides being held in a separate facility also refused to appear for questioning.
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"It's regrettable that the witnesses disregarded the authority of the people and the parliament by ignoring their obligation to attend," said committee chairman Kim Sung-Tae.
There are no legal grounds for forcing witnesses to attend a parliamentary hearing, although they can be held in contempt and face a maximum five-year prison term for not doing so.
"Choi Soon-Sil is at the core of the parliamentary probe," said Jung You-Sub, a lawmaker from Park's ruling Saenuri Party.
"Her reasons for not attending are not justified. The people want to hear the truth," Jung said.
Choi had been questioned on Sunday by special prosecutors investigating the extent of the president's alleged collusion with Choi in shaking down a number of major conglomerates to provide "donations" to two foundations she controlled.
Choi denied new allegations that she had stashed around 10 trillion won ($8.3 billion) abroad.
The National Assembly voted to impeach Park earlier this month, stripping away her substantial executive powers.
She remains president in name, pending a decision by the Constitutional Court on whether to ratify parliament's impeachment motion.
Earlier Monday, prosecutors seized documents during an early morning raid on the central Seoul residence of Kim Ki-Choon, who served as Park's chief of staff between 2013-15.
Kim has a long association with Park's family, having also served her father -- the late military strongman Park Chung-Hee who led the country for 18 years after seizing power in a 1979 military coup.
Those close ties have led to allegations that he must have been aware of the inappropriate influence that Choi -- dubbed a "female Rasputin" by the local media -- wielded over the president.
Park allegedly leaked confidential documents to her friend, and allowed her to meddle in state affairs -- including the appointments of senior officials.
