Russia is boasting that a long term spy in Nato country Estonia spilled secrets to Moscow from Britain's MI5 secret service and other Western intelligence agencies.

His espionage meant that the KGB knew the scale of intelligence activities by the American National Security Agency in Europe long before Edward Snowden's disclosures, it was alleged.

Soviet-era KGB officer Uno Puusepp was allowed to join Tallinn's KAPO secret service after the break-up of the USSR - and during at least a decade and a half as a double agent for Moscow, he went on to do significant damage to the UK, US and other European Union allies, claimed the documentary.

Spy boast: Soviet-era KGB officer Uno Puusepp (pictured) was allowed to join Estonia's secret service after the break-up of the USSR - and went on to do significant damage to the UK, US and other European Union allies, the Kremlin claims

Mole: A trusted insider in KAPO, he had access to key Western secrets, Moscow says

A Russian documentary about Puusepp showed footage purporting to include classified correspondence from Western intelligence agencies including MI5 (pictured)

He was revealed as the source of evidence in 2001 used to convict Valery Ojamae, a former Russian Foreign Intelligence officer, to seven years in jail after was accused of secretly working for the British and Estonian secret services.

Pro-Kremlin television channel NTV, owned by Gazprom, revealed his role in a 40 minute film made in close co-operation with Vladimir Putin's FSB secret service.

A trusted insider in KAPO, he had access to key Western secrets in the strategic Baltic region after he was recruited to bug communications through wiretapping, according to the programme which appeared to be used for propaganda purposes at a time of sour relations between Moscow and Tallinn.

'During this time, the FSB uncloaked several large-scale anti-Russian espionage and technical actions by the U.S, Swedish, British and other special services,' claimed the programme.

Footage was shown purported to include classified correspondence from Western intelligence agencies including MI5.

'Several agents of foreign special services were convicted, and a leak was prevented of classified information via a device that was to be inserted into a Russian telecommunication cable [for] the technical penetration of the Russian Embassy in Tallinn.'

The programme's narrator stated: 'There are few people in Russia who have done more for its security than the Estonian Uno Puusepp and his handler, former KGB officer Nikolay Yermakov.'

Claim: The documentary said that 'owing to Puusepp, the scale of intelligence activities by the US National Security Agency in Europe became known before Edward Snowden came up with his disclosures'

It alleged that Estonia was the 'weakest link' in the Nato intelligence system 'largely thanks to a modest KAPO officer, Uno Puusepp' who knew the details of Western recruitment of agents deployed against Russia, and on the surveillance of Moscow's diplomats.

NTV said that 'owing to Puusepp, the scale of intelligence activities by the US National Security Agency in Europe became known before Edward Snowden came up with his disclosures'.

His controller Yermakov claimed: 'In the entire period of Uno's work, I believe the Estonian security police's work against Russia was devalued by about 80 per cent.'

Puusepp now living in Russia - was a selfless idealist who had 'always stressed that he did not want to harm Estonia as a state' and who had never received any money for the information he provided.

The son of a KGB agent, he was inspired to spy for Moscow because of the 'Russophobia' and 'fascism' he saw in newly-independent Estonia.

The film alleged Estonian intelligence services were incompetent and subservient to the United States.

It alleged Russian-speaking Estonians were recruited to snoop on Russian defence facilities including a Sukhoi aircraft design bureau in Astrakhan Region.

The former head of Estonian intelligence Raivo Aeg - dismissed by the NTV programme as 'a somewhat stupid drillmaster' - had handed Puusepp a tape of his conversation with a senior US espionage official who had warned of a Russian mole inside the Tallinn secret service.

Fearing that his cover could soon be blown, Puusepp stayed in KAPO avoiding exposure, it was claimed.

'The Americans and the KaPo leadership hunted the traitor for several years.'

But then they arrested the wrong man, Vladimir Veitman, also a former Estonian KGB officer, it was claimed.

'Of course, I was very surprised that instead of me it was my colleague Veitman who had been arrested - as far as I knew, he'd passed over absolutely no information,' said Puusepp.

'I was very surprised when they arrested my colleague, Veitman, who, as far as I knew, had not passed any information at all,' said Puusepp.

Puusepp claimed to have gone public to highlight how Ukraine is now being cajoled into the Western world in an American plot to undermine Russia.

'I have a good memory of what happened in Estonia a little over 20 years ago. In principle, exactly the same things are happening in Ukraine,' he said.

'Under the banner of democracy and various values that all normal people respect, forces led by the Americans, dark forces, come to power, and there is just one enemy - Russia.'