Lübke resigned three months before the scheduled end of his second term amid a scandal as to his involvement with the Nazi regime during World War II.

He completed his basic training first with the Westphalian Foot Artillery Regiment No.7, with which he was then deployed on the Eastern and Western Fronts.

After the seizure of power by the National Socialists in 1933 and the subsequent dissolution of the Zentrumspartei, Lübke was accused of misappropriating public funds and imprisoned; after 20 months in prison he was released, when no evidence could be produced to back up the politically motivated charges.

In 1939, just before the outbreak of World War II, he moved to a company of building engineers managed by the architect Walter Schlempp.

[1] In February 1945 Lübke was charged by Speer with setting up a "post-war office for planning prefabricated housing" alongside architect Rudolf Wolters.

After the war, Lübke returned to his career in politics, becoming a member of the West German CDU party, being appointed Minister of Agriculture in the state parliament of North Rhine-Westphalia in 1947.

On 29 June 1964, at a press conference in Berlin, Prof. Albert Norden, one of GDR's chief Communist propagandists, alleged that Lübke acted as an informer for the Gestapo (secret police) during the war [2] and at the very least he had been aware of the use of slave labour on his projects; building plans bearing his signature and containing concentration camp barrack blocks were advanced as evidence of his complicity, but these were dismissed in the West as East German and Eastern Bloc propaganda.

Lubke stated in Berlin on 19 July 1964, "Our young people must learn more about the devotion and the willingness to sacrifice themselves that marked the men and women who rose against Hitler.

"[3] In September 1966 Lübke's office claimed that the document with his signature on display in Munich was a "forgery" and was Communist inspired.

[4] The historian Tony Judt has observed that Lübke's presidency, like the chancellorship of Kurt Georg Kiesinger, showed the "a glaring contradiction in the Bonn Republic's self-image" in view of their previous Nazi allegiances.

Arteriosclerosis of the arteries in both his brain and his limbs was becoming increasingly noticeable, leading to serious speech disorders, declining physical mobility, and progressive memory loss.

Lübke was a poor public speaker and was frequently subject to ridicule, especially near the end of his term of office when his age and his failing health started to affect his memory and general cognitive abilities.

He frequently forgot where he was (Lübke: "When I talk to you today in...eh... in.." Voice from the crowd shouting: "Helmstedt!"

Tapes from Lübke's speeches were collected by the German satirical magazine Pardon and distributed on a best-selling record.