Police will question the head of a civic group that filed a criminal complaint over main opposition Democratic Party(DP) chief Lee Jae-myung's controversial airlifting from Busan to Seoul after a stabbing attack earlier this month.

Seoul Hyehwa Police Station said it was set to question on Thursday Public Welfare Committee secretary general Kim Sun-hwan, who previously filed complaints against a Seoul National University Hospital(SNUH) professor and two DP officials.

Prior to the police questioning, Kim said he planned to ask why the DP chief opted to fly aboard a medical helicopter to have surgery at Seoul National University Hospital when he could have had the same surgery at Pusan National University Hospital. Kim said he would request an investigation into alleged abuse of power.

Last Monday, Kim's group accused the SNUH doctor that performed the surgery on Lee of defamation for alleging that there was no doctor at the Busan hospital capable of performing such an advanced surgery to treat internal jugular vein damage.

The group accused Lee's chief of staff and DP Rep. Cheon Jun-ho and DP Supreme Council member and Rep. Jung Chung-rae for abuse of power, coercion and obstruction of official duty.