Police are investigating a possible breach of Zespri's intellectual property rights after kiwifruit varieties were transferred and planted in China illegally.
Growers in China alerted Zespri to potential plantings in April last year and Zespri said it had provided evidence to New Zealand police.
Zespri spokesperson Dave Courtney said the company and police were now trying to get to the bottom of it.
"Through our own networks in China we became aware of illegal plantings of two varieties in China, small areas of our Gold 9 and Gold 3 varieties.
"Since then we've been working here in New Zealand to pursue how they may have got across to China, and take action accordingly to protect our [intellectual property] invested in that plant variety."
The plantings were a concern for Zespri despite their small size, Mr Courtney said.
"When you invest significantly in developing your own varieties and growers invest accordingly as well to buy licence to graft across... then we have to take it very seriously to protect that investment."
Other varieties had been found growing illegally in China in the past, he said.
"We are aware that our original variety, Hort16A, is up in China... We've moved on into the Gold 3 varieties [and] our whole plan is to try and build value into the variety over time.
"So clearly people taking hold of the variety and passing it on outside of our strategy is not particulary helpful to industry or growers."