Arizona Coin Collector wrote:

I was curious if the counterfeit coin problem exist
due to how the coins are made, or the ease of the
raw material that counterfeiters can get? Changing
the coin specification, and making sure the raw
material to make the coins can only be made and
sold to the Royal Mint.

An interesting thing happend a few years ago with the New Zealand $2
coins. The specifications were sent to the BRM and they made the coins
from 1990-1996. The South African mint came in with a lower bid in
1997, and the contract was awarded to them, using the same
specifications. However, not long afterwards, there seemed to be a
problem with vending machines (slot machines IIRC) accepting the South
African made coins. As it turns out, it was the electronic signature.
Now, this is the weird part...the fault was not with the South African
Mint, they made the coins to specs...it was the BRM that screwed it
up. Long story short, most of the 1997 NZ$2 were returned to the South
African Mint (at THEIR expense). This caused a shortage of this date/
denomination. The NZ$2 coins are again being minted by the BRM, using
the wrong specs, but consistent with the 1990-1996 issues.