And although the documents themselves may pertain to events long since over, the culture of secrecy which has seen them locked away until 2037 is as alive as ever, say campaigners.

The Windsors files: More to follow, in 2037

Andrew Ecclestone from the Campaign for Freedom of Information says those occupying the corridors of power today remain reluctant to throw open their filing cabinets to outsiders.

"There are huge swathes of public life which remain secret and behind closed doors."

Though it is claimed that most records deemed worthy of storing are made public after 30 years, there remain several exemptions which allow the government to deny this access for 50, 75 and, in the case of the Windsor papers, 100 years.

The official papers are traditionally released in batches, normally eliciting a rash of news stories.

There are huge swathes of public life which remain secret and behind closed doors

Andrew Ecclestone

The latest tranche of documents, released on Thursday, relate to King George VI's personal interest in bringing the survivors of the Russian royal family to the UK.

They also cover MI5 suspicions about American actor Paul Robeson, Trotsky's failed bid to claim asylum and lurid rumours about Hollywood siren Tallulah Bankhead and some Eton schoolboys.

Despite recent talk of "open government", Mr Ecclestone says there is still plenty of scope in the Freedom of Information Bill, currently before the Commons, to suppress records indefinitely.

No access

Documents will still not be released if they relate to the development of government policy or are part of an investigation by the police or other government body such as the Nuclear Safety Directorate.

Tallulah Bankhead: An Eton collar?

Although the Lord Chancellor has to approve all variations to the so-called 30-year rule, critics worry that too few safeguards exist to prevent the systematic burying of files.

Civil service mandarin Sir Michael Bichard drew fire for voicing his concern about full disclosure in a staff memo last year.

"Even when information does not carry a security classification, our responsibility is to keep it to ourselves," he told members of the education department.

"That's the mindset which needs to be overcome. Sir Michael is already under a duty to give out information," says Mr Ecclestone.

Unsecretive service

Surprisingly some of the government's most secretive enclaves have rallied Prime Minister Blair's calls for greater openness.

Under Stella Rimington and her successor Stephen Lander, MI5 has marketed itself as the cuddliest of the secret services.

MI5: The carpets are blue

The intelligence agency placed job ads in the papers, opened a website and set about dispelling the popular "myths and misunderstandings" fostered by its decades in the shadows.

It also claimed not to be fanatical about secrecy.

Office politics

This week MI5 boldly announced that the staff canteen serves a mean Chicken Madras and that the carpets in its London HQ are blue.

How much the carpets cost to fit is a slightly more touchy subject at Thames House, however.

MI5 and its sister service MI6 have been resisting the disclosure of a National Audit Office report into the refurbishment of their swish offices.

With an estimated overspend of �226m, the Commons' Intelligence and Security Committee has suggested the government's decision to suppress the report had more to do with embarrassment than national security.

Despite such criticism, the document now being prepared for release has been heavily censored.

Spy in the sky: "What are you looking at?"

Behind such episodes, it is tempting to see patrician arrogance or, more worryingly, sweaty-palmed paranoia.

According to several newspaper reports, Whitehall has begun to see security threats in the most innocuous places.

Few of those queuing for London's latest tourist attraction, the towering London Eye Ferris wheel, would regard themselves as potential spies.

However, bosses at the nearby Ministry of Defence have reportedly voiced concerns that passengers are being afforded a glimpse into their top secret offices.

Simon Sherrard from counter-surveillance firm CCS detects hysteria is such suggestions.

"At that distance and with the movement of the wheel, however good the camera or listening device you had, you wouldn't get a thing," he says.

"What would you be able to see anyway?"

That's a good question. Maybe we should ask them.