A 500-tonne gap in China's gold consumption data is fueling talk that the central bank took advantage of weak prices last year to bulk up its holdings of the precious metal.
The last time the Chinese central bank said it increased its gold holdings was nearly five years ago, in early 2009. Officials have since then repeatedly insisted that they do not view gold as a useful asset for diversifying the country's $3.8 trillion mountain of foreign currency reserves.
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But the latest official figures show that China imported and produced far more gold in 2013 than its citizens bought. This chasm suggests that the central bank was a buyer in the gold market last year in spite of its protestations to the contrary, say analysts.
The China Gold Association published data on Monday showing that Chinese demand for gold surged 41 per cent to 1,176 tonnes last year, making it all but certain that China overtook India as the world's biggest consumer of bullion.
Yet Chinese import and production volumes were even stronger. China imported 1,158 tonnes of gold via Hong Kong, more than double its 2012 total. Domestically, production of bullion rose 6 per cent to 428 tonnes. On top of that, China also imported gold directly through Shanghai, though these numbers have not been published.
Adding up the reported and estimated figures, Na Liu of CNC Asset Management calculated that China's "apparent gold consumption" exceeded 1,700 tonnes in 2013, more than 500 tonnes higher than reported.
"We would not be surprised to hear the People's Bank of China announce a new, significantly higher figure, if it chooses to do so," Mr Na said. The PBOC has said that its gold reserves have been steady at 1,054 tonnes since April 2009.
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But central bank buying is only one of the explanations for the chasm between China's apparent and actual gold consumption.
Liu Xu, an analyst with Capital Futures in Beijing, said that companies in the jewellery market may have also built up their gold stocks and that commercial financial institutions such as banks have also been adding to their holdings. Neither would show up in the gold demand data, which measures final consumption.
"It's not only about increases in official holdings. It's more accurate to say that every level of society, from individuals up to banks, has been allocating more to gold," Mr Liu said. "Wealth is expanding and people have limited investment channels, so gold is attractive."
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Moreover, the Chinese jewellery industry has also grown quickly and exports of finished products would not necessarily be captured by the gold data.
The price of gold rose every year from 2001 until 2012, soaring from $271 per ounce to $1,670. But last year its bull run ran out of steam, and prices fell 23 per cent. The precious metal has clawed back about 5 percentage points this year.
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Speculation has been mounting in recent months that the Chinese central bank might announce updated figures for its gold holdings, but Mr Liu said the recent rebound in prices could lead it to remain quiet, for fear of sparking a jump in the market.
The central bank has said the global gold market is too small relative to China's foreign exchange reserves to serve as a viable channel for asset diversification.
Even if the Chinese central bank's gold holdings were twice as large as officially reported, they would still account for roughly 2 per cent of the country's official reserves, well below the norm in more developed economies.