A German academic has unearthed evidence showing former U.S. Secretary of State Henry Kissinger once discussed a coup with disgruntled Nazis to overthrow the West German government in the 1970s.

Kissinger and Richard Nixon were aggrieved at the left-leaning government of the day's burgeoning friendship with the hardline East German government.

Kissinger became the contact man for a secret spy network made up of old Nazis and elite aristocrats aimed at torpedoing the plans formulated by Chancellor Willy Brandt.

Secret: Henry Kissinger in the 1970s in his White House office in Washington. He gave advice to a secret network made up of old Nazis and elite aristocrats

By the end of 1970, Kissinger was offering the spies advice on how to deal with Brandt's Social Democratic government.

The group he became embroiled with was called 'The Little Service' and was formed by the conservative Christian Democratic Union (CDU), which was allied with Bavaria's Christian Social Union.

One agent who visited Kissinger quoted him saying, 'It might be possible to overthrow the current government, but it remains to be seen whether this would involve risks which could put a Christian Democratic Union (CDU)/ Christian Social Union (CSU) government in great difficulty.

Whether Kissinger, the architect of the disastrous secret bombing of Cambodia in the Vietnam War which paved the way for the Khmer Rouge regime and its hideous genocide programme, approved of the plan to usurp the elected government of the day is unclear.

Revealed: Kissinger even discussed the possibility of a coup to overthrow the government of Chancellor Willy Brandt

The group he became embroiled with was called 'The Little Service' and was formed by the conservative CDU party.

Brandt pursued a policy of engagement with the German Democratic Republic, convinced it was better to build bridges with the dictatorship to defuse Cold War tensions rather than always being at loggerheads. For the all-white, all male conservatives of the CDU, this was too much.

They wanted West Germany to face off against the Soviet-backed regime in the belief that isolation would make it crumble. It was out of this belief that its private spy organisation, made up of many former Gestapo and SS men as well as titled barons and counts, was formed.

Political scientist Stefanie Waske spent seven years researching letters from politicians from the Christian Democratic Union and its Bavarian sister party the Christian Social Union, and her results are to be published next year; potentially embarrassing timing for Chancellor Angela Merkel who in November 2013 will seek re-election as CDU chancellor for the third time.

Waske approached Kissinger for comment but he refused, as did many of the noblemen who worked for the The Little Service which came into being in 1969 after the party lost its first general election since the postwar republic was formed in 1949. Details of her research are published in the current edition of the German intellectual weekly Die Zeit.

The catalyst for the spy group was Brandt's decision to recognise post-WW2 borders dividing Germany and a pledge Brandt gave that his state would not use violence against the Communist one in the east.

Conservative MP Karl Theodor Freiherr zu Guttenberg, who was the grandfather of the disgraced former defence minister who had to resign last year after it was discovered he cheated on his doctorate, held a meeting in the autumn of 1969 with former chancellor Kurt Georg Kiesinger and leading CDU and CSU politicians, the CSU being the Bavarian wing of the party.

'They decided to form an information service for the opposition,' said Waske. 'It was a secret spy service.'

Beliefs: The Berlin wall. The catalyst was Brandt's decision to recognise post-WW2 borders dividing Germany and a pledge Brandt gave that his state would not use violence against the Communist one in the east

The former head of the BND, Germany's domestic intelligence agency, was tapped and he offered up a ready-made web of informants across the globe in countries as far apart as the US, France and Saudi Arabia.

Hans Christoph von Stauffenberg, the cousin of the man who tried and failed to kill Hitler in the July 1944 bomb plot, was chosen to head the network.

Casimir Prince of Sayn-Wittgenstein, who would later only narrowly miss imprisonment for the CDU's party donation scandal of a decade ago, was recruited to raise the hundreds of thousands of D-marks necessary to fund the network.

He collected from conservatives in industry, many of whom had previously supported Hitler, and who now viewed with suspicion the apparent coziness developing between Brandt and the Communists.

The first act was to open a secret 'back channel' to Kissinger who was keen to know what the Soviets were up to at all times, including their puppets in East Berlin.

The treasurer of the group was Alfred Seidl, a former Nazi who acted as the chief defence lawyer for Hitler deputy Rudolf Hess.

'In 1971 Brandt was talking about the administration of Berlin with Leonid Brezhnev in Yalta and Stauffenberg’s informants were delivering secret information to the conservatives who were discussing it with Kissinger,' said Waske.

The intelligence gleaned came from eavesdropping, intercepted mail, informers and telephone taps. The Little Service ran for a decade, lavishly funded and with probably more success than the state intelligence agencies which were riddled with East German moles.

It was Helmut Kohl, who came to power in 1982, who disbanded the network. It was Kohl who promoted Angela Merkel - who grew up in East Germany - to become the party leader: now she will have serious political bullets to dodge about her party's murky past before polling day next year.

It was Helmut Kohl who came to power in 1982, who disbanded the network - it was him who promoted Angela Merkel to become the party leader