The Japanese Government has banned some imports of Australian barley after pesticides five times the normal limit were detected.

Key points: High levels of the pesticide azoxystrobin were detected

High levels of the pesticide azoxystrobin were detected The shipment came from ITOCHU Corporation

The shipment came from ITOCHU Corporation Authorities said azoxystrobin had been used as a fungicide for grains, fruit and vegetables around the world and was safe

Hundreds of thousands of cereal products containing the barley are now being recalled.

The pesticide azoxystrobin was detected in a shipment of Australian barley from ITOCHU Corporation that arrived in August.

The Japanese Ministry of Agriculture, Forestry and Food is now investigating and analysing all shipments of Australian barley.

Almost half of the 85 tonne export has already been used in food products and most likely already eaten, but ITOCHU said the quantity and concentration of pesticides detected did not pose a health risk.

Nevertheless, food company Nissin Cisco has voluntarily recalled 315,000 of its cereal products.

The Japanese Ministry of Agriculture, Forestry and Food has banned future shipments of barley from ITOCHU, but this will not impact exports which already have approval.

ITOCHU apologised but said the quantity and concentration of pesticides detected did not pose a health risk. ( ABC News: Simon Royal )

"ITOCHU says something possibly happened between harvesting and shipping, perhaps during the cleaning process, but they are still investigating," the ministry's Tetsuo Ushikusa told the ABC.

"It's very unlikely that it suddenly appeared in the fields."

"In the last 14-15 years, azoxystrobin has never been detected from Australian imports — not even a tiny amount."

The Japanese Government has given ITOCHU until April 27 to provide the results of its investigation.

The ministry said azoxystrobin had been used as a fungicide for grains, fruit and vegetables around the world and was safe.

In a statement, ITOCHU apologised and said it was working hard to make sure it never happened again.