A fresh mystery has emerged in the search for a Belgian tourist feared dead after disappearing in northwest Tasmania.

Celine Cremer’s vehicle was known to be in the track’s car park since at least June 20, however members of the public have come forward and it’s possible her white Honda CRV was there days earlier.

She was reported missing on June 26 but was last seen more than a week earlier in the Philosopher Falls area near Cradle Mountain.

Investigators want to speak to a walker who visited the waterfall at around 2.30pm on June 18 but stressed they were not in any trouble.

“We urge you to make contact as you may be able to assist us in establishing Ms Cremer’s movements prior to her going missing,” Tasmanian authorities said in a statement.

Members of the SES searched a number of tracks using all-terrain vehicles on Saturday.

Expert medical advice provided to police indicates she would not have been able to survive freezing weather conditions.

-AAP