Adelaide woman Rachael Moritz was reported missing on December 30.

Adelaide woman Rachael Moritz was reported missing on December 30.

A missing woman whose vehicle is believed to have been used in a bikie related murder could be in Western Australia.

South Australia Police looking for missing Adelaide woman Rachael Moritz believe she may be interstate.

The 20 year-old was reported missing on December 30.

Police have an unconfirmed report that Ms Moritz was at Adelaide Airport on the morning of December 23 and that she was in the company of a middle aged woman at that time.

While police understand she spoke to a family member on New Year's Day, it is important that police speak with Ms Moritz to confirm she is safe and well.

Detectives have no information to suggest that Ms Moritz is being held against her will.

Police believe the woman's Mazda sedan was used in the shooting of Jason De Ieso in November.

Mr De Ieso had limited links to the Finks bikie gang.

The Crime Stoppers caller who provided the information about the sighting at Adelaide Airport and the woman who was with Ms Moritz at the airport are urged to contact police.

Anyone who has any information is asked to contact Crime Stoppers on 1800 333 000.

- with AAP