Oslo police arrested the woman Thursday morning and charged her with receiving stolen property, Aftenposten reported.
A police officer was killed in the holdup at the Norwegian Cash Service or NOKAS in Stavanger in April 2004. Thirteen men are on trial in the case.
Some investigators believe the theft of two paintings by Edvard Munch from the Oslo museum that bears his name was designed to distract investigators from the NOKAS job. The paintings, "The Scream" and "Madonna," are still missing.
During court proceedings this week, prosecutors revealed much of the money stolen in the holdup was unusually old and worn -- and covered in glass dust after the thieves used a burst of automatic weapons fire to shatter plate glass windows.