The far-right Alternative for Germany (AfD) banned the lead candidate for the upcoming European Parliament elections in June and said he would urgently step down from the party's board.

The public demotion came after Maximilian Krah told an Italian newspaper that not all members of the Nazis' elite SS unit, which was involved in major war crimes during World War II, were war criminals.

Krah, 47, had already been under scrutiny after authorities in Brussels searched his offices at the European Parliament in connection with one of his assistants who was arrested last month on suspicion of spying for China.

German media have alleged that Krah has had ties himself to China and also Russia.

The scandals involving Krah come at a most inconvenient time for the AfD - only a few weeks before the party is hoping to make big gains at the European election. It had been riding high in the polls last year but has become less popular this year after millions of Germans protested its radical far-right stance.

In addition to Krah, the no. 2 on the AfD’s list for the European Parliament election, Petr Bystron, last month separately denied allegations in a Czech daily that he may have received money from a pro-Russian network.

AfD's top party board said in a statement after an emergency meeting to discuss Krah's recent missteps that there had been "massive damage to the party in the current election campaign, for which the lead candidate had provided the pretext."

It said Krah took full responsibility and will resign from his position on the federal executive board with immediate effect. It wasn't immediately clear if he was still running for the European Parliament.

The latest party crisis was triggered by an interview Krah gave last week to the Italian newspaper La Repubblica, in which he said, "I will never say that anyone who wore an SS uniform was automatically a criminal," German news agency dpa reported.

When asked whether the SS were war criminals, he replied: "There was certainly a high percentage of criminals, but not all of them were criminals."

In reaction to that interview, France's far-right leader Marine Le Pen from the Rassemblement National party indicated that Krah had overstepped a red line. So far, the Rassemblement National, or RN, had been working together with the AfD in the European Parliament, but now the French far-right is considering ending its cooperation with the AfD on the European level, dpa reported.

RN party leader Jordan Bardella said on TF1 that "I think that the AfD, with whom we have worked together in the European Parliament for five years, has crossed lines that are red lines for me," dpa reported.