Tori Rees was last seen on July 30 and is believed to have relocated to the Sydney area. 

The 17-year-old is of Caucasian appearance and between 155 and 160 centimetres tall with long dark brown and blue eyes, police said. 

She is believed to be around the Bankstown, Merrylands or Blacktown areas. 

Serious concerns are held for her safety, according to police.

Anyone with information is asked to contact Lake Illawarra Police on 4232 5599 or Crime Stoppers on 1800 333 000.