Mexico has quietly purchased nearly 100 tonnes of gold bullion, as central banks embark on their biggest bullion buying spree in 40 years.

The purchase, reported in monthly data published by Mexico’s central bank, is the latest in a series of large gold buys by emerging market economies intent on diversifying reserves away from the faltering US dollar. China, Russia and India have acquired large amounts of gold in recent years, while Thailand, Sri Lanka and Bolivia have made smaller purchases.

Central banks became net buyers of gold last year after two decades of heavy selling – a reversal that has helped propel the price of bullion to a series of record highs. On Wednesday gold was trading at about $1,510 a troy ounce, down 4 per cent from a nominal record high of $1,575.79 reached on Monday.