The suspect named as Ulli S. was detained on arrival at Frankfurt airport on Tuesday after being transferred from France, where he had been held on the basis of a European arrest warrant, prosecutors said in a statement.

Ulli S. "maintained long-standing business relations with Russian arms manufacturers" in his role as managing director of a machine tools company in southern Germany, the prosecutors said.

The European Union imposed sanctions on Russia following its annexation of Crimea in 2014.

They include a ban on exporting "dual-use goods and technology" that can be used for both military and civilian purposes.

Ulli S. is accused of signing contracts in spring 2015 with a Russian arms manufacturer for six tools needed for the production of sniper rifles, worth around two million euros ($2.2 million).

To conceal the transactions, Ulli S. allegedly used other companies he had founded as well as another Russian company.

The deliveries were made in the summer and autumn of 2015 through third-party companies in Switzerland, and in one case via Lithuania, the prosecutors said.

Installation and training services were also provided to the Russian company in 2015 and 2016.

In early 2015, Ulli S. is also accused of acquiring four sniper rifles from the Russian company for 22,000 euros for testing purposes and importing them into Germany.

He is accused of falsifying the date of that contract in order to pretend the transaction was not covered by EU sanctions.