Blurred images of mystery girl released

A mystery girl at the centre of a nationwide search launched by Victorian Police may still be in danger.

Police have released two blurred images of the young girl - aged between four and six at the time - and appealed for help in finding her.

Leading Senior Constable Julie-Anne Newman on Tuesday said investigators feared for the girl's safety after she was pictured inside what could be an Australian apartment in May last year.

An Australian Federal Police spokeswoman on Wednesday declined to comment further on the search except to say Victoria Police were leading the investigation.

It is unusual for police to release images of a child and it's unclear whether those made public on Tuesday are photographs or stills taken from a video.

"The girl appears to be in an apartment or similar which is well furnished, with modern, large windows and is possibly overlooking a city skyline or other tall structures," Sen Const Newman said.

"It is believed the girl is in Australia because an AFL game is being played 'live' on television in the background."