A South Korean court on Wednesday assigned five state attorneys to defend disgraced former president Park Geun-hye, following her defence team's resignation last week in protest at the extension of her detention period until April next year.

Park is standing trial accused of bribery, abuse of power and coercion, having been forced to step down in March after parliament voted to impeach her at the end of 2016.

She has been held in detention since late March, although under South Korean law a defendant in a criminal trial at a lower court can be detained for a maximum of six months.

Citing concerns that Park could destroy evidence if she was released, the Seoul Central District Court issued an additional arrest warrant on Oct. 13 in order to extend her detention by six months.

The court's move prompted her entire defence team to quit in protest at a session on Oct. 16. Having lost her legal team, Park gave health reasons for her failure to attend a session three days later.

"After witnessing the collapse of the presumption of innocence and the principle of investigation without detention, we concluded that our efforts to defend Park will be meaningless," Park's former lawyer, Yoo Yeong-ha, told the court last week.

"The court's decision to issue an additional arrest warrant will remain as one of humiliating moments in South Korea's judiciary history," Yoo said.

A Seoul Central District Court spokesman said five state attorneys had been appointed to take over Park's defence.

Citing court sources, Yonhap news agency reported the new defence team would have to review about 120,000 pages of court documents to prepare for upcoming hearings.

Park's supporters have asked a United Nations body to investigate whether Park was being prevented from getting proper medical treatment and possible violation of her human rights due to her detention.