According to the World Gold Council (WGC), global central banks bought 157.5 tonnes of gold in the second quarter, up 63 percent quarter-over-quarter and up 137.9 percent year-over-year.

In fact, there is a school of thought that suggests euro zone members use gold as collateral for sovereign debt issuance to keep bond yields.

We put together a list of the countries with the biggest official gold holdings as reported by the WGC last week. We also included the percent of their foreign reserves they have in gold.

Note: CBGA refers to the Central Bank Gold Agreements. The first Agreement (CBGA 1) ran from September 27, 1999 to September 26, 2004. The second Agreement (CBGA 2) ran from September 27, 2004 to September 26, 2009. The third Agreement (CBGA 3) will run for five years from September 2009.