Oji Paper and Nippon Paper have admitted to fabricating the amount of recycled content in their printer and copier paper for more than 10 years.

The companies apologised for having misled consumers and customers. Nippon Paper president Masatomo Nakamura is to resign over the issue, although Oji Paper president Kazuhisa Shinoda will stay on in his role.

According to some reports, Fuji Xerox has decided to withdraw recycled Nippon Paper stock from sale, with Canon and Konica Minolta expected to follow suit.

Nippon Paper told reporters that some of its products that claimed to be 100% recycled in fact contained less than 60% recycled stock, and Oji Paper admitted that envelopes billed as containing half recycled materials may have contained as little as 5%.

Shinoda said that demand for the paper had meant increased shipments of the products, although the levels of recycled material had not matched that growth in volume.

The companies are among five Japanese firms being scrutinised for misrepresenting the environmental credentials of their paper products.