Police are appealing for public assistance to help locate missing teenager Acacia Williams.
The 18-year-old has been missing since November 13 but was believed to have been seen in the CBD on November 23.
Police and family hold concern for Acacia's welfare due to the length of time she has been missing and as she has a medical condition.
Acacia is known to frequent the Melbourne, Melton and Geelong areas.
She is described as about 155cm tall and perceived to be of Aboriginal appearance, with a thin build, olive complexion and dark long hair.
Investigators have released an image of Acacia in the hope someone recognises her and can provide information regarding her current whereabouts.
Anyone who sees Acacia is urged to call Box Hill Police Station on 8892 3200.
