A sitting lawmaker was summoned by the prosecution Thursday over alleged sexual assault.

Rep. Sim Hag-bong, who left the ruling Saenuri Party in August, is suspected of sexually assaulting a woman in her 40s at a hotel in Daegu, a major city in North Gyeongsang Province, on July 13.

The woman initially said that she was sexually assaulted but later changed her statement, saying there was no coercion.

Prosecutors of the Daegu District Prosecutors' Office said they are focusing on whether there was coercion and the 54-year-old lawmaker persuaded the woman to change her statement.

"I am sorry for causing worries," Sim told reporters before entering the prosecutor's office.

He declined to answer questions on whether he admits to the allegation.

The National Assembly ethics committee passed a motion weeks ago in a unanimous decision to expel Sim.

If the motion passes the assembly's plenary session, it will be the first time for a sitting lawmaker to be ousted for an ethical reason.

His defection lowered the number of seats of the ruling party in the 298-member parliament to 159. (Yonhap)