Japanese food company Ito En on Tuesday issued a huge recall of Chinese-grown tea after some of it was found to contain illegal levels of pesticide residue.

The firm said it was recalling about 400,000 packages of Oolong tea after spot testing revealed pesticide residue levels above Japanese food safety limits.

Ito En said it started testing the tea from China's southern Fujian province after another Japanese teamaker announced last month it had found similarly high pesticide levels in its China-sourced tea.

"We found the higher levels of pesticide residue after conducting voluntary tests following another company's announcement about Oolong teabags," an Ito En spokesman told AFP.

But he insisted the findings were not an imminent health risk, adding that the firm had not received any complaints from customers.

The spokesman said the tea had passed sample testing performed in China, which has been hit by a string of food safety scandals in recent years.

The recall also comes as China-Japan trade, worth over $340 billion annually, has taken a hit in the wake of a territorial row over an East China Sea island chain claimed by both countries.

Ito En said it may strengthen its testing of the traditional-style Oolong tea and has sent company officials to China to investigate the matter.

"We will suspend sales of the relevant products until we find out the cause," he said.

The tea under recall has expiry dates from mid to late November 2013.

China is trying to crack down on product safety violations after a series of high-profile scandals.

In 2008, the industrial chemical melamine was found to have been illegally added to dairy products to give the appearance of higher protein content in China's biggest food safety scandal.

At least six babies died and another 300,000 became ill after drinking milk tainted with melamine.

The same year, thousands of Japanese people fell ill after eating pesticide-laced Chinese dumplings.

Earlier this year, a Chinese dairy producer was ordered to suspend production after a cancer-causing toxin was found in its infant formula.