GE Free is calling for an Otago University report on New Zealand's clean, green image to be withdrawn.
The anti-genetic engineering, lobby group says the report raises questions about its ethical and academic credibility and it wants the raw data released for peer review.
The Otago University study found it would be highly unlikely that the introduction of genetically modified pasture would damage the country's so-called clean green image overseas.
Some 515 first-time overseas visitors at the Auckland international airport were asked a series of questions including whether the introduction of GM pasture would stop them visiting the country in future.
The study found more than 90% of respondents either definitely, somewhat or slightly agreed the introduction of GM pasture would not stop them from visiting New Zealand.
GE Free says the data was manipulated and the report is flawed. It says Otago University should focus more on finding out the true value of promoting New Zealand as a clean, green trader instead.
Otago University associate professor John Knight said last week that the 'myth' that the introduction of GM pasture would harm the country's image in the eyes of potential tourists, should be laid to rest and should not be a factor when considering the introduction of particular GM technologies.