The Paper Federation of Great Britain said at least 960,000 tonnes of recovered paper were exported last year, 48% higher than the official figure of 650,000 tonnes.

Environment head David Gillett said Asia had upped demand in recent years.

"The extra 310,000 tonnes makes a big improvement to the UK recovery level by increasing the total from 5.25m to 5.56m tonnes. This is 44.4% of consumption rather than 41.9%."

Customs & Excise used vague threshold calculations, said Gillett. His federation worked with the Independent Waste Paper Processors Association and British Recovered Paper Association.