Maximilian Krah, a leading member of the Alternative for Germany (AfD), is standing down from the far-right party’s executive, party leaders Alice Weidel and Tino Chrupalla told journalists in Berlin on Tuesday.

Krah has been in the headlines for weeks following reports of possible links to pro-Russian networks and to China, as well as possible financial dealings.

German prosecutors are currently examining whether an investigation should be opened.

Krah, the party’s lead candidate in next month’s elections to the European Parliament, moved last month to fire his assistant, parliamentary aide Jian Guo, following allegations that Guo was spying for China.

German police arrested Guo on suspicion of spying on April 22.

Krah told the Junge Freiheit (Young Freedom) weekly, which is close to the AfD, that he aimed to concentrate on his work in the European Parliament and stand back from German domestic politics.

He said he had taken the decision months ago and denied it had anything to do with the Guo affair.

The AfD’s signature issue is a hard-line anti-immigration stance, and the party is profiting from increased concern among many German voters over rising numbers seeking asylum in the country.

The party is polling nationally at around 18%, amid high dissatisfaction with Chancellor Olaf Scholz’s three-party coalition.

Its support reaches to around 30% in Thuringia and Saxony, where state elections will be held in September.