Minotaur and the Labyrinth

Most of us have heard the legend of the Minotaur and Labyrinth. Part of the thought on this subject is that the "royal Minoan palace on Crete" (1) was the bases of the myth and this is shown by currency coins showing the Labyrinth on one-side and the Minotaur on the other (2). However, I see some issue with this situation.
　
While I'm not sure who would have authorize the production of coins at this time it would seem reasonable that they would not have wanted to draw attention to where the palace kept it valuables. Likewise it would seem that non-trusted people's would be not allowed to enter the palace's storage area for security purposes. This means at the time there was most likely very little knowledge of the design of the storage area in general public circulation. It can be further reasoned from these that it is unlikely the storage area of the palace was 'the Labyrinth' based on the lack of the knowledge of the layout of the storage area available at the time and those doing the authorization of coin production would not have wanted to draw attention to the royal storage.

Links:
1 http://en.wikipedia.org/wiki/Labyrinth
2 http://en.wikipedia.org/wiki/Minotaur
http://en.wikipedia.org/wiki/Ancient_Greek_coinage