A standoff in Sydney’s north has ended after police grabbed a man who’d perched himself on a balcony for the entire day following the discovery of a woman’s body.

The man appeared on a balcony rooftop of the Leura building, off Brown Street in Chatswood, on Monday morning.

It came after a trademan on his way to work saw the body of a woman, aged in her 30s, lying in an alley nearby.

Luke Bladen Williams Hamilton said tried to establish there was “no sign of life”, but soon realised the woman was dead.

“It was pretty obvious due to the harshness of the scene,” he said via Facebook.

Mr Hamilton said he also saw smears of blood on a wall about five metres away.

The man spent the entire day on the rooftop, at times appearing agitated and dangling his bare feet over the edge, as a negotiator spoke to him with the help of a Korean translator.,

Two officers wearing helmets and harnesses were positioned in an area above him.

About 7.15pm, there appeared to be a struggle on the roof area and the man was taken into custody.

Temperatures in Sydney climbed to about 30C during the day and the man was given cigarettes and water.

The woman’s body remained below, covered by a police tent, and detectives were unable to retrieve it due to the ongoing operation.

Police have refused to confirm reports the dead woman was the man’s girlfriend.

The man took off his shoes in the late morning and was handed cigarettes by police, but sat near the edge of the roof for most of the afternoon.

The macabre situation drew a crowd of spectators.

Rohan Pulakhandam who works at the nearby Hoyts cinema saw the man just 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.”

– AAP