A man has been arrested after coming down from a high-rise awning, ending a 12-hour stand off that began when the body of a woman was found in an alleyway nearby.
The woman's body was found earlier in the morning near the Chatswood apartment in Sydney's north.
Police spent all day negotiating, using a Korean interpreter to communicate with the man who appeared distressed and at times dangled his legs from the awning above a 27th-floor balcony of the building.
The body of the woman, believed to be in her 30s, was found by a pedestrian in the alley off Brown Street near the Chatswood train station about 6:30am.
Police are yet to reveal her cause of death but are treating the incident as one of domestic violence, and believe the couple were in a relationship for a number of weeks.
A man is seen on a ledge on an apartment building in Chatswood, Sydney, Monday, October 9, 2017 (AAP)
With the temperature in Sydney hitting almost 30C negotiators handed the man a cigarette and a bottle of water just after 11am but they've been unable to coax him inside.
The site has been cordoned off as police negotiators - including a Korean speaker - continue to talk with the man at the top of the building.
A tent has been erected around the woman's body which is directly below.
Luke Bladen Williams Hamilton discovered the woman's body on Monday morning when heading to work.
Mr Hamilton told AAP he had to establish there was "no sign of life" before he knew for sure she was dead.
"(But) it was pretty obvious due to the harshness of the scene," he said via Facebook.
"I don't know if she actually fell. There were blood smears approximately five metres away on a wall six-foot high."
Rohan Pulakhandam, who works at the nearby Hoyts cinema, saw the man on the balcony roof after 11am.
"As soon as I saw the man it was just gut-wrenching," Mr Pulakhandam told AAP.
"The fact that he's been sitting for so long in the heat with the sun shining directly on him - he mustn't be feeling very good."
Call Lifeline on 13 11 14 for 24-hour crisis support and suicide prevention.
