NSW Police are appealing for public assistance to help locate a 10-year-old boy who was last seen at the Queen Victoria Building on Sunday.

The concerned family of Subo Jin, known as Bob, say his disappearance is out of character after he went missing at 1pm.

Officers from Sydney City Police Area Command commenced a search of the area without success on Sunday and are appealing for assistance to find him.

Bob is 153 centimetres tall and has short black hair and a fair complexion.

He was wearing a dark grey shirt with “Zombie squad” on it, green shorts, blue and red shoes and a hat with an elephant on it on Sunday.

Anyone who has seen Bob or believes they know his whereabouts is urged to contact Sydney City Police or Crime Stoppers on 1800 333 000 or nsw.crimestoppers.com.au.