"I will faithfully respond to prosecutors' questions," Woo told reporters at the special prosecutors' office in Seoul, as quoted by the Yonhap news agency.
The prosecution also team suspects Woo of involvement in the dismissal of former presidential inspector Lee Seok-soo, after he looked into the Mir and K-Sports foundations controlled by Choi.
Political scandal around the South Korean president broke out in late October 2016, when media reported that Park had allowed her friend Choi, who held no official post, to edit her speeches and influence the country's policy. Choi is also accused of pressuring South Korean corporations and extorting money from them for her non-commercial funds.
On December 9, the South Korean parliament voted to impeach the president in the wake of the scandal. The court has six months to decide upon the validity of the impeachment. If proved valid, presidential elections will be held within two months.