BERLIN — It started with an investigation into a suspected terrorist plot by an army soldier aimed at top government officials. But it quickly uncovered a larger problem.

Military police searching through barracks turned up Nazi-era military memorabilia that revealed a much broader presence of far-right extremists in the German Army’s ranks, something commanders are now accused of having long ignored.

They are currently investigating 275 cases involving accusations of racism or far-right extremism stretching back six years, according to the Defense Ministry. The number represents a small minority in a force of nearly 180,000. But nearly 70 percent of cases have emerged in the last year and a half, pointing to an accelerating problem that German military authorities are only now scrambling to address.

“In the past, individual cases were always examined, but it wasn’t seen or understood that these cases are not isolated, but there are networks and connections, also to extremists on the outside of the armed forces,” said Christine Buchholz, a member of Parliament from the opposition Left party.