Germany is grappling with a wave of espionage threats from Russia and China

 Six suspected espionage suspects have been arrested in Germany this month alone, sparking a flood of accusations of Russian and Chinese espionage, the BBC reported on Sunday.

For the far-right Alternative for Germany (AfD) party, this proved particularly embarrassing, as its two main candidates in June's European elections found themselves in the crosshairs.

Assistant MEP Maximilian Kra, who heads the party's list, was arrested on suspicion of espionage for China. Jian Ge is accused of being an "employee of the Chinese secret service".

Prosecutors have also opened a preliminary investigation into the politician himself regarding alleged payments from pro-Russian and Chinese sources. Mr Kra denies any wrongdoing.

A few days earlier, Petro Bystron, the second name on the AdG list, denied allegations that he received money from the Voice of Europe website, which European intelligence says was a front for Russian intelligence.

But the accusations go far beyond the ADH. Two German citizens of Russian origin were arrested on suspicion of conspiring to sabotage Germany's military aid to Ukraine, and three Germans were detained on suspicion of planning to transfer advanced engine designs to Chinese intelligence.

"It's really unusual that three networks that were [allegedly] engaged in a kind of espionage for Russia and China were caught almost at the same time," said Noura Chalati, a research fellow at the Leibniz Center for the Contemporary East.

In all three cases of espionage, the efforts of Germany's domestic intelligence agency BfV are believed to have played a crucial role.

"Our security agencies ... have significantly increased their counterintelligence efforts," Interior Secretary Nancy Feiser said.

The arrests came shortly after Chancellor Olaf Scholz returned from wide-ranging talks with Chinese President Xi Jinping in Beijing.

A few months earlier, a senior official of Germany's BND foreign intelligence service, Karsten L., had gone on trial on charges of passing classified information to the Russians in exchange for payments of around 400,000 euros.

A public crackdown on suspected espionage could be one way to send a signal to friends and foes alike that Berlin takes security seriously.

The BND and BfV said they do not comment on ongoing operations.