Labour is calling on the Ministry for Primary Industries to provide more information about problems with New Zealand sheep intestine exports to China.
The meat industry used to export partly processed sheep intestines, which the industry calls "green runners", to China for processing into sausage casings.
But halfway through last year, the Ministry for Primary Industries (MPI) placed a temporary ban on the export of partially processed sheep intestines to China in response to concerns raised by that country's authorities.
However, the Ministry is refusing to elborate on what China's concerns are, saying trade matters are sensitive and that it would be innappropriate for it to comment.
Labour's primary industries spokesperson Damien O'Connor says the Ministry needs to provide more information.
"We understand that in this case the export of casings - and it's worth about $98 million (or was last year) - that it's been blocked. And we don't know why, we're struggling to find out and MPI can't provide us with any information," he says.
"Well I think there are glitches in the process and MPI are probably once again under-resourced and not able to deliever to the Chinese the requirements to meet the market."
The Ministry for Primary Industries says the temporary export ban does not apply to finished casings.