They will probably not be a professional 'spy' but may have some basic instruction in espionage methods. In the UK, an agent, more formally known as a ' covert human intelligence source', is someone who secretly provides information to an intelligence officer. Such spies are dubbed 'illegals' because they operate without any of the protections offered by diplomatic immunity. In some cases they may operate in 'deep cover' under false names and nationalities. Some intelligence officers may operate under non-official cover to conceal the fact that they work for an intelligence service - posing as a business person, student or journalist for example. They may operate openly, declaring themselves as representatives of foreign intelligence services to their host nation, or covertly under the cover of other official positions such as diplomatic staff or trade delegates. They will be highly trained in espionage techniques and the use of agents. Intelligence officers are members of intelligence services. Spies working for states fall into two categories: intelligence officers and agents.

What is a spy agent