The Herald on Sunday has learned the Broadcasting Standards Authority has not upheld a complaint - finding that TVNZ had already taken sufficient action.
In March, Henry mocked Greenpeace spokeswoman Stephanie Mills' appearance after an interview, saying "that is a moustache on a lady".
The BSA's refusal to condemn Henry has angered Greenpeace, which may now boycott the top-rating morning television show.
What? Greenpeace is going to boycott Breakfast? Goodness - our day is getting better by the moment. Though we wouldn't go as far as some and label Henry a national treasure, he is a breath of fresh air. He says what he thinks, and he pushes the boundaries. But surely that's an improvement on the clones that TVNZ and its rivals constantly churn out. And so, for your viewing pleasure, and because we can, let's relive the moment ...