Thailand increased its gold reserves for the third time in a year in June, while concern about debt and sluggish growth in developed economies sent the price to record highs on Wednesday.
International Monetary Fund (IMF) data showed the Thai central bank added 18.66 tonnes, bringing its reserves to 127.524 tonnes, overtaking Singapore as the world's 25th largest holder of the metal, up from 31st.
The IMF's international finance statistics showed Russia, Kazakhstan, Greece, Ukraine and Tajikistan also added to their reserves two months ago, reflecting the trend among central banks to park more of their foreign exchange holdings in gold.
"The market generally expects central banks with growing reserves and small gold holdings to buy gold," said Jesper Dannesboe, senior commodity strategist at Societe Generale."
"So I don't think that is particular surprising, but it does support the bullish story," he said.
Central banks are expected to remain net buyers of gold this year, after buying more gold in the first half of this year than in the whole of 2010, according to a World Gold Council report released in July.
Global central banks as a whole bought 73 tonnes of gold in 2010, according to metals research firm GFMS.
Thailand became the latest Asian central bank to add to its gold reserves in June, as bullion hit record highs buoyed by investor discomfort over anaemic economic growth and debt crises in Europe and the United States.
Spot gold was last quoted at $1,668.10 an ounce at 0845 GMT, up 0.6 percent on the day, having touched a record $1,672.65 earlier in the day.
Earlier this week, Korea confirmed it had bought 25 tonnes of gold in June and July, increasing its bullion reserves for the first time in over 10 years.
The IMF data showed Russia, the world's eighth largest official holder, added 5.85 tonnes, bringing its reserves to 836.715 tonnes. Russia has added to its gold reserves every month for the past five years, according to the IMF's data.
Kazakhstan's reserves rose for the third time this year, by 3.11 tonnes in June to 70.434 tonnes, Taijikistan's reserves rose 0.04 tonnes to 3.036 tonnes and Greece and Ukraine added 0.03 tonnes each, bringing their official holdings of gold to 111.506 tonnes and 27.744 tonnes, respectively.