“Operation Neptune”: The most brazen disinformation campaign of the Cold War

The best way to spread lies is to mix them with truth. On September 15, 1964, Lubomir Štrougal, former secret service agent and now Minister of the Interior of the Czechoslovak Socialist Republic (ČSSR), invited representatives of the world press to his office in Prague to tell them about a sensation. Several boxes recovered from the Black Lake on the German-Czech border shortly before, in July 1964, had contained original documents from Office VI of the Reich Security Main Office (RSHA), he announced. The material concerned the activities of National Socialists in Austria, France, Italy and Great Britain and also contained lists of Czechoslovak Gestapo agents; it had been sunk in the lake, which was up to 40 meters deep, in the spring of 1945.

Numerous documents were shown on television screens. Representatives of eastern and western media read in amazement an exchange of letters between Hermann Göring, RSHA chief Reinhard Heydrich and the governor general of occupied central Poland, Hans Frank, about the “final solution to the Jewish question”, documents about sabotage in northern Italy and South Tyrol, and the report of an “SS history commission” that in 1938 had investigated the reasons for the failure of the putsch by Austrian National Socialists against the Dollfuss government in Vienna on July 25, 1934.

The list of Czechoslovak collaborators could not be published “for reasons of state security,” the minister said. However, the names of former Gestapo employees, some of whom still hold important positions in the Federal Republic, would be made public later. Some of the documents were being further examined, it was said.

1800 pages of files

The reaction of the world press was impressive: the “Süddeutsche Zeitung”, the “Frankfurter Rundschau” and “Le Monde” reported from Paris on September 16, 1964, and the “New York Herald Tribune” just one day later. The “Neue Zürcher Zeitung” even printed two reports from the “Agence France Presse” on the following days – the first apparently did not seem sufficient to the editors responsible. However, Štrougal’s reports only made it onto the front pages of leading newspapers in the Eastern Bloc. The SED’s central organ, “Neues Deutschland”, for example, depicted a box being carried to the shore and on that Wednesday headlined its second most important article with the words “Secret files from the Black Lake – Nazi agents on sale in Bonn today”.

Lubomir Štrougal was delighted with the success, even though he had been extremely nervous beforehand. His actual task at the press conference was to spread a blatant lie in a credible manner. The story he told the journalists was essentially made up. This is shown by almost 1,800 surviving pages of files from the Czechoslovak secret service StB on “Operation Neptune” – as well as the memoirs of the StB officer Ladislav Bittmann, who came up with the whole operation. For the German secret service historian Thomas Rid, who works in the USA, it was the “brazen disinformation campaign of the Cold War”, as he writes in his book “Active Measures. The Secret History of Disinformation and Political Warfare” (Profile Books, 528 pages, 16.99 euros).

The starting point was the unsuccessful search for a gold treasure from the Nazi era in Lake Toplitz in the Austrian Alps, about 70 kilometers east of Salzburg. Two diving expeditions there in 1959 and 1963 only found boxes of supposed pound notes from the SS counterfeiting workshop in the Sachsenhausen concentration camp. Inspired by this, the state television of the Czechoslovak Republic asked the authorities in Prague in the spring of 1964 for permission to search in two lakes in the Bohemian Forest, which are halfway between Munich and Prague.

Permission was necessary because the Black Lake (Černé jezero) and the Devil’s Lake (Čertovo jezero) are both located just a few hundred meters from the Czech-German border, i.e. in the restricted area of ​​the military-guarded Iron Curtain between the Eastern Bloc and the West. Rumors circulated about both lakes, according to which Wehrmacht or SS units were still active here at the end of April 1945. Did they hide dark secrets, similar to those in Lake Toplitz?

The ministry approved the search and assigned a number of recreational divers to the camera team. It was no coincidence that 33-year-old Bittmann was one of them. On his first dive in the Black Lake, he took a closer look at the bottom, came across a soldered metal box stuck in the mud at a depth of twelve meters – and had an idea.

In a memo to his direct superior, Major Jiri Stejskal, he suggested placing a few more boxes on the lake bed before the next, larger-scale dive in the summer. They could be filled with genuine documents from the Nazi era, supplemented by clever forgeries. The idea was obvious to Bittmann, as he was the deputy head of Department 8, which was responsible for disinformation and “active measures” in the StB. The “discovery” of the boxes was to be documented by TV and the alleged material, both the genuine and the manipulated material, was to be presented to the world press shortly afterwards.

“Operation Neptune had three goals,” Bittmann reported in 1972 in his book “Secret Weapon D,” which he published four years after defecting to the West: “First, it was to support the public campaign against the statute of limitations for war and Nazi crimes in West Germany; second, to promote anti-German resentment in formerly occupied Western European countries such as France and Italy; third, to curb the presumably extensive activities of the BND on Czechoslovakian territory through false reports.”

This was the aim of the hints about lists of Czechs who had collaborated with the Gestapo during the war. Bittmann assumed that the BND had relied on such collaborators when setting up its spy network in Czechoslovakia: “If the disinformation campaign were successful, the BND would have to temporarily break off contact with those agents in order to find out whether its agent network was really at risk.”

Bittmann and Stejskal also drove from Prague to the Black Lake on the evening of June 19, 1964. With them were Josef Houska, then head of the StB, and a KGB advisor. In the next car followed additional StB employees, including a diver, as well as four boxes, carefully locked and sealed. However, there were no documents in them, neither real nor fake, just empty papers. During the long drive, Bittman noticed that Houska was worried. He probably feared that his career could be over if “Operation Neptune” failed.

The cars arrived at the Black Lake while it was still dark. The men launched an inflatable boat, Bittmann put on his diving suit and prepared to sink the four crates. But the other diver lost a flipper, which was now floating around in the lake. They were not allowed to attract anyone’s attention when they “discovered” the crates. By around five in the morning, the StB men had finished hiding them and (almost) erased all traces.

On June 25, 1964, the TV team returned accompanied, this time by a helmet diver. The StB employees cleverly ensured that the search began at the Teufelssee, where, to everyone’s astonishment, sunken German explosive charges were discovered – they were detonated on a nearby meadow for the camera. Then the search continued in the Schwarzer See. Nothing was found there for a week. Disappointment was already spreading when Bittmann drew attention to the places where he had sunk the boxes.

Very carefully, because they could be vermin, they were recovered using pulleys and taken to Prague. There they were x-rayed: there were no explosive charges. The boxes contained waterproof envelopes with papers that were immediately confiscated without anyone being able to look inside.

In the meantime, the KGB had sent almost 30,000 pages of genuine Wehrmacht and SS documents from German stocks captured in 1945 to Prague from Moscow; the StB contributed further papers from its own stocks. Bittmann and his colleagues from the disinformation department had to select in order to achieve their goals. Initially, these included the report of the SS “Historical Commission”, documents from Office VI of the RSHA, the correspondence on the murder of the Jews, papers from the office of SS chief Heinrich Himmler and the like; further material could be “discovered” in the “recovered” papers as required and made available to the public later.

However, many documents were ruled out because Soviet evaluators had written comments on the originals in Cyrillic script. This could not be erased without a trace, and any expert would have immediately noticed that documents allegedly sunk in 1945 and recovered in the summer of 1964 were unlikely to have been commented on by the KGB or the GRU military intelligence service. In Bittmann’s view, this spoke in favor of authenticity, because no disinformation expert would devalue an elaborately forged document in this way. Conversely, however, this trick could have been used to distract from the fact that the documents were actually forged.

It is not possible to clarify to what extent the work of the BND in the Czechoslovak Socialist Republic was disrupted by the allegedly discovered, but in fact never existing, lists of former Gestapo collaborators; there is no reference to Bittmann’s action in the 15 volumes of the BND’s Independent Commission of Historians, published between 2013 and 2022. Josef Houska credited “Operation Neptune” and himself with the postponement of the statute of limitations for murder for an initial four years, which the Bundestag decided in 1965 after intensive debate – although there was no demonstrable connection. There are also no known resentments against the Federal Republic in the countries formerly occupied by the Wehrmacht that had anything to do directly or indirectly with the documents released by the public about the alleged discovery in the Black Lake.

In fact, however, the campaign may have fuelled the sharpening of the debate about the Nazi past in the Federal Republic in the mid-1960s. And it was a model for similar disinformation campaigns, such as those carried out by the GDR State Security against Federal President Heinrich Lübke from January 1966, which defamed him as a “concentration camp builder” based on a few, but artificially falsified, documents.