When it came to winning the war against Hitler’s sophisticated propaganda machine, the BBC hit upon an ingenious idea: tell the unvarnished truth.

An academic trawl of the corporation’s archives has revealed that while the Nazi regime used puppet broadcasters such as William Joyce – nicknamed Lord Haw-Haw – to spin messages of German invincibility, the BBC was choosing to broadcast detailed news of Britain’s military setbacks. The decision was part of a deliberate strategy to win the hearts and minds of the German people, says Dr Vike Martina Plock of the department of English at Exeter University, who discovered memos from the time during research at the BBC Written Archives Centre in Caversham Park, Reading.

The BBC wanted its German language service – set up in 1938 at the time of the Munich crisis, when it became apparent another world war was likely – to become a trusted news source, which meant even defeats had to be truthfully reported. Notable examples include the 27 November 1942 report of the German bombing of Toulon and the scuttling of the French fleet to avoid its capture, and the 6 April 1940 report – days before the invasion of Norway – of the sinking of 52 Norwegian ships by the German navy, resulting in the death of 392 people.

The policy appears to have paid dividends. Despite attempts to jam programmes and prosecute listeners in Germany for tuning into enemy broadcasts, the BBC soon became one of the most significant sources of information for people living under Nazi rule.

The number of programmes transmitted to Germany grew dramatically during the war to include features, political satire, songs and music. One show pitted Hitler against Hitler, playing recordings of his speeches to highlight how he regularly contradicted himself. In another, a Berlin housewife with a broad lower-class Berlin accent told listeners some home truths about everyday life in Germany. BBC producers believed the character could help them subtly criticise Nazi leaders in a manner that was relevant to ordinary families in Germany.

Accurate news, however, was the bait used to draw in German listeners. One BBC memo, marked private and confidential, dated 23 March 1942 recorded: “There were roughly 80 broadcasts [this] week in the German language, of which about 75 were given by English speakers. Broadcasts were arranged on a cyclical basis so that German listeners could be sure of hearing Britain at the hour throughout each day.

“News was the magnet which attracted the audience and consequently talks followed the news, in the belief that the audience attracted by the news would continue to listen to a talk for which they might not otherwise tune in. It was the aim to be first with the news whether good or bad and in practice bad news was usually given first. In this way each bulletin ended with better news. It was the tone of the last items which left a ‘taste in the mouth’. Broadcasting of bad news helped with the reputation for truthful statement which was the basis of our service.”

Broadcasting of bad news helped with the reputation for truthful statement which was the basis of our service BBC memo, March 1942

Although the BBC used several German intellectuals living in exile in Britain as feature writers and translators, the news presenters were almost exclusively British. Plock, whose research was funded by the Leverhulme Trust, said that the broadcaster feared its objectivity and neutrality would be compromised if known Nazi objectors or political refugees were allowed to speak directly to listeners in Germany.

“It is fascinating to see how the BBC provided the German public with accurate information during the war and thereby began to re-educate individuals who had been living, willingly or unwillingly, with 12 years of Nazi propaganda,” she said. “To be effective in exposing Nazi propaganda as lies and teach German listeners to become responsible citizens of a peaceful, unified Europe, the BBC German Service had to first gain their trust. Offering impartial news was therefore very important, even if it meant broadcasting information about Britain’s military setbacks. Listeners who heard these news bulletins were inclined to believe in Britain’s superior military strength. If the Allies could openly admit defeats, it was believed, they must be extremely confident, convinced of their eventual victory over Nazi Germany.”

Likewise, reports about the way British people were contributing to the war effort were used by the corporation to emphasise the country’s belief in victory. An internal BBC report on bulletins and programmes in Germany broadcast between 5 and 10 May 1941 observed: “Our certainty of victory is based on moral and material considerations. Our conviction of fighting for a just cause might perhaps be emphasised more frequently, not only in terms of social and economic reform, but also from a purely moral point of view. Conviction of victory based on superior industrial power may not for the moment convince the German listener, but accounts of work in factories and on farmers bring home to the Germans our growing production. There is too little said of the British attitude towards bombing: because we are certain of victory, we can stand plenty of bombing.”

The BBC also monitored reports in German newspapers and radio broadcasts put out in response to its news bulletins. One memo records: “Exaggeration, excitement, threats and extravagance in all forms were avoided. It was a trap into which the Russians were inclined to fall. There was evidence that Germans listened in large numbers to British news, but not to Russian. Several prosecutions had occurred in one day in one place in Germany recently and two of those convicted had been listening in public to the BBC.”

The BBC German Service became a model for similar operations in other countries – by 1943 the corporation was transmitting programmes in 54 languages. It was discontinued only in 1999 and was seen as having played a key role in shaping Germany’s postwar public service broadcasting sector.