Letting agents were warning of shortages across the UK, Arla said.

BBC: RELATED BBC SITES

British agents in this field operate both in the UK and abroad, where their mission is to protect British assets.

BBC: Who's being spied on?

It was to help the UK to assess the risk of an attack using biological agents by providing important information about their likely dispersion in the open air during the Cold War.

BBC: RELATED BBC SITES

An investigation for BBC London's Inside Out programme last year revealed agents in the capital were arranging to swap foreign licences into UK ones via a Hong Kong licence, which the UK does accept automatically, to bypass the rules.

BBC: Driving licence law change 'to halt illegal trade'