WELLINGTON (REUTERS) - New Zealand has suspended apple exports to China after the discovery of a fungus that causes fruit to rot, government officials said on Wednesday.

The Ministry of Primary Industries (MPI) said the fungus, which can rot fruit after harvesting, had been discovered in three consignments of apples sent to China, which regarded it as a threat to plant health in that country.

It said the fungus, which was limited to those shipments, posed no threat to food safety and had been tracked down to a small number of growing and packing sites, which China had asked be suspended from exporting.

"(The New Zealand) Industry has informed us that in response to the rot being detected - and considering this apple export season is almost over - it has voluntarily suspended all apple exports to China for the remainder of the season," the MPI said in a statement.

The discovery of the fungus is the latest hiccup in New Zealand's food exports to China, which so far this year has seen dairy products banned for high levels of nitrates and possible botulism contamination, and the delay of meat imports because of confusion over export certificates.

New Zealand apples are harvested from February to April and kept in cold storage until sold when export markets have no local supplies.

The MPI said officials from both countries were looking at the risk of the fungus being introduced into China.

Apple exports to China were worth about NZ$15 million (S$15.6 million) in the past year, but are seen having strong growth potential.

China is New Zealand's second biggest export market, and a significant buyer of agricultural goods, especially dairy produce, with the Fonterra Co-operative Ltd a major supplier of milk powder, the source ingredient for infant formula.