German Foreign Ministry spokesman Martin Schaefer told Ukrinform, Censor.NET reports.
If there are grounds for arrest, Germany expects them to be presented, Schaefer said.
The diplomat offered reassurance that his country is keeping a close eye on the developments in relations between Ukraine and Russia that are not only each other's major neighbors but also those of the European Union. Berlin has also taken note of Sushchenko's arrest, he added.
Schaefer stressed that the federal government would like all the journalists - whether in Germany, Russia, Ukraine or any other country in the world - to be able to freely do their work.
Earlier, members of Moscow's Public Monitoring Commission found Ukrinform news agency correspondent Roman Sushchenko in Lefortovo prison. The Lefortovo court of Moscow remanded the journalist in a two-month custody on charges of espionage (article 276 of the Criminal Code of the Russian Federation).
Later, Ukraine's Information Policy Ministry confirmed the detention of Sushchenko. The ministry said its legal department was collecting necessary information on the circumstances and reasons for the detention.
In turn, the FSB claims Ukrainian journalist Sushchenko is an agent of the Main Intelligence Directorate of Ukraine's MoD.
According to lawyer Mark Feygin, charges against Sushchenko will be brought on Friday, Oct. 7.
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