"Britain's Guardian newspaper said the document was being interpreted by developing countries as setting higher levels of allowable greenhouse gases per person for rich nations than poor ones.
Though the document, posted on the Guardian website, does not contain any figures on emissions targets or cuts, the newspaper said the concern had been raised in a "confidential analysis" it had seen.
It claimed the analysis said developing countries would not be allowed to emit more than 1.44 tonnes of carbon per person by 2050, compared with 2.67 tonnes for rich nations, but did not say what the figures were based on.
There were concerns that the document, said to be worked on by representatives of a small group of countries including Britain, the United States and Denmark and circulated to only a handful of other nations at Copenhagen, was sidelining the United Nations negotiations.
Dr Smith said New Zealand had been consulted about the document."