According to The Daily Telegraph, Ms Choi had reportedly threatened to leave her boyfriend after she discovered he was already married. Mr Seo was estranged from his wife and also had a son.
Ms Choi's friend Moossoo Yoon told the publication that she had seemed “very strong and positive when I spoke to her on Thursday”.
“I told her she was now of the marrying age and she said there was someone but it was complicated and she wasn’t happy,” Ms Yoon said.
“She had rowed with him over that the day she died.”
Ms Choi’s body was discovered by a pedestrian in a lane near Chatswood train station on Monday morning at about 6.30am.
If you or someone you know is experiencing domestic violence, contact 1800 Respect (1800 737 732).