The Prime Minister's office is demanding a Chinese immigration agency remove a picture of John Key from its website, which appears to show he endorses the organisation.
The China-based agency's website said it had been working in New Zealand immigration for 10 years and claimed to have helped with 20,000 applications.
It prominently featured a large picture of Mr Key, his signature, and the words "recommended to you with sincerity by John Key".
Several other images of Mr Key with Chinese officials were on the site. The agency said it had a "fast government channel to reach New Zealand directly" and a strategic partnership with the New Zealand Government. "We promise you can to get your visa 100 per cent for certain," the website says. "We are the only authorised immigration agency in China that works only on New Zealand applications."
But New Zealand officials said the claims on the website were false.