WELLINGTON, New Zealand (AP) -- Concerns over low-level traces of the industrial chemical melamine in one of New Zealand's highest-priced dairy exports have spread to Australia as officials consider whether the manufacturing process causes the contamination, a food safety official said Tuesday.
New Zealand's Tatua Cooperative Dairy Co. on Monday stopped exports of the dairy protein lactoferrin, used mainly in baby formula, after tests showed it contained four parts per million of melamine.
Milk products that have been blamed for killing at least four children in China and leaving tens of thousands of others sickened had melamine levels of about 2,500 parts per million.
Tatua said a Chinese customer told its agent two weeks ago that melamine had been detected in its lactoferrin powder. Further tests in both China and New Zealand on Sept. 22 and 23 confirmed the low-level contamination, chief executive Paul McGilvary said Monday.
Food safety officials are now investigating whether lactoferrin manufactured by Westland Milk products on South Island and Australia's Victoria state dairy company, Tatura, which uses the same process, are being contaminated with melamine by the manufacturing process it uses.
New Zealand Food Safety Authority tests have shown melamine contamination of about 1 part per million in Westland's lactoferrin.
"This trace level may have arisen out of this (company's) specific, unique (manufacturing) process," said NZFSA director of compliance and investigation, Dr. Geoff Allen.
Investigators are waiting for test results on samples sent to New Zealand a week ago, which also may have implications for Victoria's Tatura plant.
Apart from four tests on lactoferrin manufactured by Fonterra, Tatua and Westland, another 112 tests had been conducted on other New Zealand dairy products, Allen said.
Fonterra is a partial owner of China's Sanlu Group, the first of 22 Chinese dairy companies whose products were found to contain high levels of melamine.
Allen said low-level contamination was not considered a health hazard.
"Without exception, all results fall below the safety threshold set by NZFSA and also fall below any safety limits set by other food safety regulators around the world, including (the) U.S. and E.U.," Allen said.
Lactoferrin is usually sold as a minor ingredient and industry officials have claimed that any contamination in the end product would be undetectable, and only measurable in parts per billion.