Zespri's first delivery of this season's kiwifruit to Europe has been delayed after mice were found on the ship.

During standard clearance processes in Zeebrugge, Belgium, the pests were discovered in the fruit holds of the charter vessel.

The fruit would be quarantined while inspections were under way, says Zespri chief operating officer Jason Te Brake.

"Zespri takes fruit quality incredibly seriously, no fruit will be released unless both Zespri and relevant regulators are confident of mitigation measures."

He says the start of the season in Europe will now be pushed back a week with a second charter vessel due to arrive in Zeebrugge on Saturday.

"That fruit will undergo an inspection process before being released to customers.

"We're now working with our customers and our distribution partners to ensure we can commence the European sales season as quickly as possible to meet strong consumer demand."

Jason says this is the first time in two decades that Zespri has encountered the issue.

"We have a proven track record over 20 years of providing only the highest quality fruit and building a brand people trust and we won't compromise on that.

"We have had a number of successful arrivals in other markets already this season, we are working with our shipping partner and insurers to understand the cause and to put additional processes in place to avoid this occurring again."

-RNZ.