BERLIN (AP) — A new study highlighting the extent to which former Nazis protected each other from prosecution in post-war West Germany should serve as a warning to the legal profession, the country's justice minister said Monday.

The study details how thousands of Germans who committed crimes during the Third Reich were protected by former Nazi party members holding key positions in the post-war legal system.

Researchers found that more than half of all senior officials in the Justice Ministry in the 1950s and 1960s were ex-Nazis who — through inaction or intentional sabotage — systematically protected fellow former members of Adolf Hitler's National Socialist party from prosecution and shaped West Germany's legal code for decades.

Some had been prosecutors and judges during the Nazi era and were apparently recruited for their legal expertise after the war.

Presenting the study in Berlin, Justice Minister Heiko Maas said it illustrated the importance of teaching even jurists to resist injustice, as many of those concerned appeared to have seen no contradiction between their role meting out harsh sentences on behalf of Hitler's regime and then working within the post-war democratic system.

Among them were Eduard Dreher, a Nazi-era prosecutor who sought the death sentence for petty criminals, and Max Merten, who was involved in the deportation of Jews from occupied Greece during the war.

While U.S. authorities tried 16 Nazi-era jurists and lawyers in 1947, convicting most of them, West Germany was reluctant to do the same. No Nazi-era judges and just one prosecutor were put on trial after the establishment of the West German Federal Republic in 1949.

"Knowledge of history can sharpen people's senses for situations where human rights and the rule of law are called into question again," said Maas.

He cited recent government pressure on the legal systems in Turkey and Poland, and U.S. presidential candidate Donald Trump's threat to jail opponent Hillary Clinton if he wins the election, as examples of attempts to use the justice system for political ends.

The so-called Rosenburg Project, named after a 19th-century villa in Bonn where the Justice Ministry was first based after the war, covers the period from 1950 to 1973. It was conducted by independent experts commissioned by the government and given unprecedented access to classified documents over the past four years.

The study is part of a broader effort to scrutinize the influence of Nazis after the war. Among the other steps being undertaken are a reform of Germany's murder laws, which contain elements of Nazi-era ideology, and the rehabilitation of around 50,000 gay men convicted under laws criminalizing homosexuality until 1969.

"Injustice can appear in the guise of the law," said Maas, arguing that history provided a strong argument against stripping away suspects' basic rights in times of emergency.

He wants the failings of German jurists during the 20th century to become a compulsory part of future legal training.