If would want only the physical gold bar, I would be very careful not to buy the fake bar. Just buy the real gold bar. Any category of things in the world can contain one or two fake items. For example, there is occasional falke $100 bill. You have to be careful so that you do not accept the fake bill. But you cannot say I want to quit using the US currency altogether just because of occassional fake bills.
But if you do not want to own physical gold, you may not need to worry about the alleged fake bar. You just buy the gold contract or shares and hold them and then sell them at a higher price. You just make money. Gold is in the beginning of gigantic long term bull market at least 5 to 10 years. The street.com says: Follow Paulson and buy gold. The street.com says: Gold $2,400 . Goldman Sachs analyst says Gold $1,200 by year end. So if you worry too much about unrelated things, how do you make money in the gold market ? If there is a fake nutrition bar in the grocery store, would you quit eating all nutrition bars? would you quit eating all foods altogether because there might be something impure in any category of food?
Warning: 1. You must not listen to my posting blindly. 2. You must consult own adviser before buy or sell. 3. You must verify everything before believing it. 4. This is personal opinion only. not a solicitation to buy or sell security. Thanks