The Australian police are investigating the disappearance of five Vietnamese exchange students in Adelaide City, as they were believed to go missing at different times between last month and this month, according to Australian broadcast news service 7 News.

The broadcast news service reported that the five Vietnamese students who came to study at Hamilton Secondary College in Adelaide varnished without a trace, with one not heard from in more than four weeks.

The latest case is Sunnie Nguyen, 17, who was last seen at her host family’s home in South Plympton, Adelaide on Monday.

Nguyen’s host mother May Zervaas said she had not seen the student since 11:00 pm on the day.

Nguyen was gone along with her backpack, laptop, personal papers, and some clothes, Daily Mail reported.

Her phone has been disconnected and her social media accounts have been wiped.

“I hope she is OK. I’m just worried because her English is not that good," Zervaas added.

Nguyen's host family told police officers that she seemed happy living in Adelaide and had no reason to run away or hide.

Her visa remains active for another three years.

Local authorities on Thursday released a statement saying that one of the girls had been located but the four others were still unaccounted for, predicting that they might have traveledd interstate.

'I hope that this is a case of, because of school holidays, kids, 17 years old, want to get together to go somewhere and not (tell) anyone,' said Lien Nguyen-Navas, a representative of the Vietnamese Women’s Association in Adelaide.

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