Ahn Hee-jung, a former rising star in South Korean politics, has been acquitted of raping a female aide in what has been the most high-profile trial in the country's #MeToo movement.
The decision prompted immediate controversy, as critics said the judicial system was male-dominated and accused courts of handing down verdicts favouring men in sexual assault and harassment cases.
Mr Ahn (53), a former provincial governor seen as a strong candidate to replace President Moon Jae-in when his terms ends in four years, was acquitted of forced sexual abuse, sexual intercourse by abuse of authority and other charges by the Seoul western district court.
“I am sorry to the public and I am so ashamed . . . I will do my utmost to turn over a new leaf, I have nothing else to say, but I am sorry,” the former governor of South Chungcheong province told reporters after the proceedings.
Mr Ahn's aide Kim Ji-eun said in a TV interview earlier this year that Mr Ahn had raped her four times during trips in South Korea and overseas.
She said she had been unable to reject her boss because of the rigid hierarchy of her office.
In March, Mr Ahn retired from political life after the accusations, although he said the sex had been consensual.
Women’s rights activists shouted “Repent!” and “It’s not over yet!” as he left the courtroom, while Mr Ahn’s supporters shouted for his accuser to be charged.
In its ruling, the court said there was not enough evidence “to substantiate the charges that his actions infringed on the victim’s sexual freedom”.
“This case involves two adults with intellect and sound judgment. There appears to be no evidence other than the victim’s testimonies that suggest physical force had been used to incapacitate the victim,” the court said, quoted by the Yonhap news agency.
With a rash of accusations against political leaders, film directors and senior industry figures, there were signs that South Korea’s traditional patriarchy was being challenged for the first time, but the court’s ruling is seen as a setback for the country’s fledgling #MeToo movement.
The verdict comes one day after a woman was convicted of secretly filming a male model in a nude drawing class at a university and distributing the video online. Activists called the police investigation “unfair”, saying police acted unusually quickly to investigate her while taking much longer to investigate spy cam cases involving men.
In a statement read out by her lawyers, Ms Kim said she would not be defeated by the “unjust” result.
“I will fight . . . until the day when those using their power to sexually abuse others are held accountable under the laws,” she continued.