Australian supermarkets and pharmacies were running out of popular baby formula Thursday after unprecedented sales reportedly due to Chinese customers trying to secure supplies.

Nutricia, supplier of top-selling formula brand Karicare, said there had been a sudden surge in demand for its products which had seen stocks plummet and left shelves empty.

Major supermarket Coles said it was trying to arrange extra shipments of infant formula. Some pharmacies were rationing sales across brands to a few cans per customer.

Media reports said Chinese residents or tourists in Australia were buying formula in bulk and shipping it back to their native country for family or sometimes sale online.

"Chinese visitors buy as many cans as they can fit into their luggage to take back to China," one manager of a pharmacy near a major international hotel in central Sydney told the Daily Telegraph newspaper.

Many Chinese people are suspicious of domestically produced milk following a major food safety scandal in 2008 in which six children died and 300,000 others fell ill after drinking milk tainted with the industrial chemical melamine.

A Nutricia spokesman did not comment on what had driven the latest spike in demand but said its products were very popular in Asia, particularly in China.

"Because they had some issues with product safety with baby formulas a few years back they look to Australian and particularly New Zealand-produced products," the spokesman told AFP.

Nutricia said it was "working with supply partners to increase production capacity by a further 50 percent over the next 12 months".