A report from the Taranaki Regional Council shows cattle have been found standing in paddocks on top of recently spread oil industry waste on a so-called landfarm, despite widespread concern that stock should not be run on such waste.
Landfarms are used to dispose of oil industry waste.
The Taranaki Regional Council, which issues consents for the operation of the landfarms, says stock should not be put on recently spread oil waste.
And a government research body that has studied landfarms says stock should be kept off the land for 12 months after the oil waste is spread.
However, while the Ministry for Primary Industries acknowledges there are risks associated with landfarming, it's leaving it up to farmers and processors to manage the risks.
The ministry is ignoring calls to enforce a withholding period to ensure the petro-chemicals, heavy metals and salts in the waste have returned to safe levels before animals are allowed on the land.
Catherine Cheung is a researcher for the environmental lobby group Climate Justice Taranaki, which has campaigned against landfarming.
She says leaving it up to farmers to manage the risks of running stock on toxic waste is not sufficient regulation.
Ms Cheung says she can't understand why Landcare Research's recommendation to play it safe and keep livestock off land for one year after the oil waste is applied is being ignored.
Taranaki Regional Council says it in no way approves of the farmer running stock on the land as the oil industry waste is being spread.
But, it says, it's not responsible for the regulation of livestock or animal welfare and food safety issues.
Climate Justice Taranaki and the Green Party say that isn't good enough, and means no-one is safeguarding animal welfare on the oil waste farms.
They fear contaminates in the waste could poison livestock and subsequently enter the food chain.
Greens energy spokesperson Gareth Hughes says it's impossible to know whether meat from the cattle on this landfarm is safe to eat as there's been no testing.
Radio New Zealand asked Primary Industries Minister Nathan Guy why there's no with-holding period for livestock.
"Oh, I think the ministry has, as I think they have told you, they have widespread testing that they're already doing. They've already started is my belief, so they are working through this process of doing further testing on these farms. Fonterra does a lot of testing as does the regional council."
Asked if he would eat meat from a landfarm, Mr Guy said that was a hypothetical question and he does not answer hypothetical questions.
The ministry hasn't been able to confirm Mr Guy's statement that its testing of products from the so-called landfarms has begun.