An office wall-clock could house a tiny TV camera

NHS Lanarkshire documents seen by the BBC say there has been hardly any secret surveillance of health staff until now.

But the Lanarkshire proposals, if enforced, would mean health staff could have their telephones tapped, their emails intercepted and their letters opened.

They could also be spied on at home and watched in their cars.

Informants could be paid to give information about colleagues or be encouraged to make friendships first in order to gather information.

Jim Devine, of the health union Unison, said that several health boards had similar proposals.

Mr Devine said: "This is not a charter to prevent thieves, this is something much, much more sinister.

"This smacks of a big brother, one party state keeping their eyes on what the staff and what the workforce are doing. It is totally unacceptable.

"I know Lanarkshire already has done and I know Lothian and Forth Valley are in discussions about introducing it and my understanding is that it may rolled out across the whole of Scotland."

Jim Devine said the proposals were "unacceptable"

The document says: "Surveillance is used by a range of government departments and public authorities to protect people from harm and to prevent crime."

It then adds: "The use of covert intrusive surveillance, directed surveillance and informants for the purposes of preventing or detecting crime or protecting the health of the public relate to matters which are devolved to the Scottish Parliament."

The document says that authorisation for surveillance must come from the chief executive, or an authorised officer in their absence.

It also discusses how some surveillance operations might work, using terms, straight out of a spy film, like handlers and controllers.

The document further says that, with the exception of the Common Services Agency Fraud Investigation Unit, the use of "covert investigative techniques by the wider NHS in Scotland has been negligible to date".

However, the Scottish Human Rights Centre warned that the authorities could face a court challenge if the powers were used against a health service worker.

Staff could be watched without their knowledge

The centre's Rosemary McIlwhan said: "Privacy gives you the right to respect for private and family life, home and correspondence.

"That covers not only your personal life, but your work life as well. So it would cover things like not being monitored at work, your telephone calls, interaction with your trade union representative."

She added: "So these proposals might cause problems and might be open to a human rights challenge."

NHS Lanarkshire said it had never used the new powers and would only do so in extreme circumstances.

The executive said health boards had been given guidance on the laws so that any covert surveillance is properly controlled and the rights of staff were protected.