Two Brazilian tourists who were doused with herbicide by a helicopter spraying gorse over the Heaphy Track deserve at least an apology, says Labour Tourism Spokesperson Kelvin Davis.

"The last thing New Zealand needs is for this couple to leave our country hurt and angry that we dumped on them and ignored them," Kelvin Davis said.

"Our reputation as a clean, green country is being put at risk like never before with the National government eyeing up parts of the conservation estate for mining and concentration camps for cattle in the McKenzie Country and with its deeply flawed Emissions Trading Scheme. This latest incident further risks our spiralling reputation.

"New Zealand Tourism cannot afford to have this type of incident occur, or if they do occur for the response to be mismanaged.

"These tourists made a deliberate choice to come on their once in a lifetime adventure because of New Zealand's clean, green image. That has well and truly been shattered and someone needs to make amends.

"While these tourists have spoken out, how many others have also had this happen to them, but just headed back home with a bitter taste in their mouths and a rash from an allergic reaction on their backs?" said Kelvin Davis.

"The Minister of Conservation should be asking serious questions as to how this could be allowed to happen, how to prevent it in future how to improve the response to tourists' concerns. It's not good enough to wave them away with bland assurances.

"The Government has just this week invested heavily in promoting specific regions. The last thing we need is for our tax dollars to be negated by a government department with sloppy practices that poison tourists," Kelvin Davis said.