A German citizen who signed a contract with the Ukrainian army but later deserted after failing to receive the promised payment has been detained by Russian law enforcement, the Federal Security Service (FSB) public relations center said on Wednesday.

Axar.az reports according to the FSB, the man arrived in Ukraine in November 2025 and signed a three-year military service contract with the Ukrainian Armed Forces. However, he deserted after not receiving the promised payment.

“The authorities are currently deciding whether to open a criminal case against the detainee under Article 359 of the Russian Criminal Code (mercenary activity),” the FSB said.