The leader of the far right Alternative for Germany (AfD) party has defended the actions of its leadership in connection with reports about the possible involvement of leading party politicians with Russia and China.
"We will draw clear consequences if these things are confirmed against Mr Krah and Mr Bystron," Tino Chrupalla said on the German public broadcaster ZDF on Thursday evening.
Both had given written assurances that there was nothing to the allegations and therefore the presumption of innocence applied.
Maximilian Krah, a member of the European Parliament is the AfD's top candidate for the European elections in June, while AfD Bundestag member Petr Bystron is in second place on the election list.
Following media reports about possible links to pro-Russian networks and possible financial payments, public prosecutors are examining whether investigations should be opened into both politicians.
Krah is also under pressure because one of his employees was arrested on suspicion of spying for China.
In the heated TV debate, Christian Democratic Union (CDU) politician Armin Laschet attacked Chrupalla: "There have never been such conditions to this extent of treason in the Federal Republic of Germany," said the former CDU candidate for chancellor.
"If you were as sure as you're acting here, would you be saying I'm sending Krah on every talk show to prove his innocence? Please don't take us and the German people for fools!"
Krah will not take part in the AfD campaign inauguration event with party leaders Alice Weidel and Chrupalla on Saturday in Donaueschingen in south-west Germany as planned. There will also be no videos with him.