The 33-year-old Russian national had just passed the Kybartai border checkpoint when her Russia-registered VW Passat was pulled over by Lithuanian border guards in the town of Kybartai on Wednesday.
A thorough inspection revealed bags with about 15 kilograms of amber in a hidden compartment of the car.
The investigation is ongoing. The driver was released after questioning, but her car and the amber are held at the Kybartai border station.