Three times as much opium was produced in Helmand in Afghanistan last year as when British troops arrived there in 2006 - and this year's crop will be even higher, according to a new UN forecast.

The UN Drugs and Crime Agency says it is a ''worrying situation'' and that output is forecast to rise not only in Helmand, but across the country for the third year in a row.

David Loyn reports from Kabul.