27/07/2017 6:29 PM AEST | Updated 27/07/2017 7:30 PM AEST

Brother Of Man Shot Dead At Sydney's Central Station Criticises Police

Danukul Mokmool was shot by police after threatening a local flower stall.

The brother of a man shot dead by police outside Sydney's Central Station on Wednesday night has criticised officers from the NSW Police Transport Command, saying they did not need to fire.

Danukul Mokmool, known as Dan, was shot dead by police around 6:45pm outside a flower stall at the entrance to the busy CBD train station. Mokomool was reportedly holding a broken bottle and scissors in his hands which he allegedly threatened the flower stall operator with.

Witnesses at the scene allege they heard the 30-year-old man tell police "shoot me".

A video posted to social media of the incident appears to show a man running from inside Eddy Avenue Florist towards plainclothes officers when four loud noises, presumed to be gun shots, are heard along with the sound of a woman screaming. The man then falls to the ground.

Mokmool's half-brother, Charlie Huynh told the ABC that Dan had battled mental health problems for at least 10 years and that police should not have felt the need to shoot-to-kill.

"They could have done something better than just shooting him," he said. "Come on, like, he was just holding scissors.

"I'm not saying that's not bad or that's good. At the end of the day he still held scissors up to a worker.

"They could've dealt with it better than what they did. They could've at least hit him to the ground, pepper spray him, stuff like that."

NSW Police confirmed the incident in a post to Twitter on Wednesday night and have now launched an investigation into the exact circumstances around the incident.

Huynh acknowledged that his half-brother may have "wanted to die" as a result of his mental state and not having taken his daily medication. He also said he was unaware the man in footage posted to social media of the incident was his half-brother until early on Thursday morning when police arrived at his house.

"I'm guessing he got really paranoid at stuff. Thinks someone was trying to kill him or what not.

"I got a knock at 4 o'clock in the morning telling us, 'did you hear about the Central Station news?' I'm like, 'no, what's wrong?'

"'Well, the person in the news is actually your brother that got shot dead.' And that's when I just dropped. I didn't know what to say. I was like just in shock."