Jeremy Page, The Times correspondent in Moscow, says that the Russian rock scandal is a deliberate shot across Western bows not to criticise.

"On the face of it, the story of a fake rock packed with surveillance equipment all sounds far-fetched. But we shouldn't dismiss it too quickly. The FSB has so far confirmed everything, and one has to ask why Russia - which has just taken on the G8 presidency - would pick a fight with Britain so gratuitously if the allegations were untrue?

"And an electronic dead-letterbox might be a useful tool for intelligence agents. There are inevitable risks in using a conventional dead-drop, for example leaving documents in a waste-paper bin, if you are under surveillance. Using the hollowed-out rock, the agents would be able to download data or upload instructions simply by walking past it.

"It sounds incredible, but stranger things have happened in the history of espionage. There is a co-operation of sorts in the international community: everyone knows that everyone is spying on each other - it's almost a game. It is just a question of deciding exactly what happens when the spies get caught.

"The timing of the release of the story on state television is very telling. The Russian Parliament has recently passed legislation requiring all of Russia's non-governmental organisations (NGOs) to register with a new regulatory body. They will have to report individually on every single financial contribution that they receive.

"The crucial allegation in the documentary, which was shown without warning late last night, was that one of the British diplomats involved in this spying ring was personally signing off grants for NGOs. It was a tenuous link, but the intended message was very clear: he's obviously a spy and he's passing NGOs Western money so that they can undermine the Russian state.

"It may seem simplistic to us, but it has played very well in Russia where they share our fascination with Cold War-style espionage antics.

"The Bill which has just passed through the Duma gives the state powers to close down any NGOs deemed to threaten Russia's territorial integrity or national security. The concerns that international and Russian NGOs have is that this regulator has been given carte blanche to decide, subjectively, whether they represent a threat.

"What, for instance, would it make of a human rights organisation working with relatives of suspected rebels in Chechnya?

"All Western governments have openly funded a number of NGOs to try to help the development of a democratic society in Russia. However, some of the organisations which the West regards as being entirely legitimate are highly subversive to Russian eyes.

"Russia's idea of democracy and an independent media is very different from the West's, and the Kremlin regards Western funding of some organisations as an attempt to undermine Russia. It has become particularly sensitive to this following the events in Ukraine last year when the Western-backed NGOs instinctively sided with Viktor Yuschenko, as the pro-democracy candidate, against the Russian-backed Viktor Yanukovych.

"Another argument that tends to confirm the credibility of the reports is that spying still goes on. Things have undoubtedly changed since the collapse of the Soviet Union, but there is still an awful lot of information around which could be of use to both sides. Russia has stepped up its intelligence activities in the West, and the West has dramatically increased its activities in the former Soviet states.

"There's a huge amount at stake. Russia is going to become the biggest energy supplier to Western Europe in the next few years. Russia also still has a huge nuclear arsenal, and is selling billions of dollars of weapons to China every year.

"So although the interest of the intelligence agencies may have switched from being political to being, in the main, commercial, that has not made the information any less valuable.

"If this is true and MI6 has been caught red-handed, history suggests that it will all be sorted out behind the scenes. It's extraordinarily embarrassing for the British intelligence services and they will never admit to it - we'll just get the sort of vague denials that we are hearing today.

"However, down the line you can guarantee there will be some sort of tit-for-tat exchange: perhaps not immediately, but British authorities will at some stage become aware of a suspect Russian activity on British soil and it will all balance out.

"Similarly, if this does lead to the four diplomats being expelled from Russia then we can expect that London will respond by kicking the same number out of Britain. Experience suggests that these sorts of intelligence disputes rarely spill over to become major diplomatic rows. At worst, it will sour the atmosphere for a while.

"If this is true, Russia doesn't need to bang on about it. It's proved its point and convinced a large majority of the Russian population that Western funded NGOs are a real threat. The best MI6 can do is keep its head down.

"The upshot of all of this for Russia will be that it is now going to be very hard for the British government to criticise the NGOs Bill, which means it will get at least one G8 member to shut up about it."

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