* LME/ShFE arb: http://bit.ly/2wZSAEz (Updates with official prices)
LONDON, Feb 14 (Reuters) - Aluminium prices touched their lowest in two months on Wednesday after a rapid build-up of stocks in exchange warehouses suggested ample supplies of the metal.
Benchmark aluminium on the London Metal Exchange traded up 0.1 percent at $2,141 a tonne in official rings after falling to $2,112.50, its lowest since Dec. 20.
Expectations that a crackdown on polluting smelters in China, the world's biggest producer and consumer, would reduce global supply helped to drive aluminium prices to the highest in six years in late December.
But stockpiles in LME-registered warehouses have surged by more than 200,000 tonnes since late last week to nearly 1.3 million tonnes, while inventories in Shanghai Futures Exchange warehouses continue to build after rising more than 600 percent last year. <MALSTX-TOTA> <AL-STX-SGH>
"There is obviously ample supply of aluminium in China and therefore scope to export at least some of that material," said Commerzbank analyst Daniel Briesemann.
"The big inflows into LME warehouses point to subdued demand in China," he added, predicting that prices could fall below $2,000 a tonne.
The rise in stockpiles was also a reminder that about 7 million tonnes of aluminium is sitting outside the exchange warehouse system after market surpluses in recent years, said Julius Baer analyst Carsten Menke.
TECHNICALS: Aluminium has fallen below its technically important 50-day and 100-day moving averages. Fibonacci support was at $2,110 a tonne.
POSITIONING: Brokers Marex Spectron said that speculators were betting on lower prices, with net short positions in LME aluminium at 6.6 percent of outstanding contracts.
U.S. TARIFFS: President Donald Trump said he was considering options to address steel and aluminium imports including tariffs and quotas. This is likely to drive up prices in the United States but have less impact elsewhere, Commerzbank's Briesemann said.
HOLIDAY: The Shanghai Futures Exchange will be closed from Thursday, reopening on Feb. 22, reducing trading activity.
DOLLAR: The dollar has weakened this week, supporting metals by making them cheaper for users of other currencies. U.S. January inflation data due at 1330 GMT could affect the exchange rate.
YUAN: Economists polled by Reuters said that the Chinese yuan would erase most of its substantial gains against the dollar since the start of the year, reducing the buying power of Chinese investors.
GERMANY: Expectations of robust demand for metals were bolstered by data showing robust growth in Germany, Europe's biggest economy.
OTHER METALS: Copper traded up 0.4 percent at $7,012 a tonne, zinc gained 0.6 percent to $3,488, lead rose 0.5 percent to $2,573, tin did not trade but was bid up 0.6 percent at $21,625 and nickel traded 1.6 percent higher at $13,660.
(Additional reporting by Tom Daly; Editing by Keith Weir and David Goodman)