MOSCOW — The Kremlin on Wednesday denied any involvement in the recent killing in Berlin of a former Chechen separatist field commander after a Russian national was taken into custody as a suspect.

“This case has no relation to the Russian state and its official bodies,” Dmitri S. Peskov, the Kremlin’s spokesman, told reporters. “I flatly deny any link between this incident, this murder, and official Russia.”

The fatal shooting on Friday of Zelimkhan Khangoshvili in a park in central Berlin raised suspicions that it was another example of Russia’s deploying an agent to target a longtime political opponent.

In particular, it added to the string of killings of Chechens who had refused to pledge allegiance to the Kremlin and Ramzan A. Kadyrov, who was entrusted by President Vladimir V. Putin to pacify the restive region with an iron fist.