The Cottonsoft toilet paper manufacturer is being criticised by environmental groups for using pulp from Indonesian rainforests to make its products.
All major suppliers of toilet paper in New Zealand were asked by WWF New Zealand, the Green Party and Greenpeace to confirm where their pulp comes from.
Cottonsoft did not respond, so a sample was sent to the United States for testing.
WWF says the sample tested positive for mixed tropical hardwood and acacia which strongly indicates the pulp fibre originates from an Indonesian rainforest.
Tests on Cottonsoft's other brand, Kiwisoft, also produced the same result.
Cottonsoft denies any wrongdoing. In a statement, corporate affairs director Steve Nicholson said all its products are certified by the Programme for the Endorsement of Forest Certification.
According to Mr Nicholson, PEFC is the world's largest forest certification programme.
Cottonsoft is owned by Asia Pulp and Paper of Indonesia. Kiwisoft and Paseo are also under APP.