The 14-year-old left a property on Dream Place in Melton South between 9 pm on Wednesday (May 1), and 5 am on Thursday (May 2).
She was last seen at Melton Railway Station around 11.50 am on Thursday.
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Police have released CCTV footage of her in the hopes that she is recognised and someone can provide information about her current whereabouts.
It is understood later that day, Olioli boarded a V/Line train at Southern Cross Railway Station heading towards Waurn Ponds around 12.50 pm.
Her family and police have concerns for her welfare since she is new to Australia.
She is described as approximately 156cm tall with a slim build, olive skin and black hair.
Olioli was last seen wearing a black hoodie and black pants.
Anyone who sees Olioli or has information on her whereabouts is urged to contact Melton Police Station.