Germany's justice ministry has launched a wide-ranging effort to examine the influence that the Nazis had on the country's legal system, including the role some German officials played in preventing former Nazis from being prosecuted after the war.

The project, 70 years after the end of World War II, comes amid a fresh push to bring surviving Nazi war criminals to justice.

In an interview, Justice Minister Heiko Maas told The Associated Press: "Too many who bore guilt covered for each other."

Among the obstacles to prosecuting former Nazis for decades after the war was that German law required proof of direct involvement in a killing for a murder charge — the only crime not covered by the statute of limitations.