Germany's intelligence agency intercepted radio messages from Russian military sources discussing the killing of civilians in the Ukrainian town of Bucha, German news magazine Der Spiegel reported on Thursday.
It said the agency presented the findings in parliament on Wednesday, without giving a source for the information.
Bucha, 37 km (23 miles) northwest of Kyiv, was occupied by Russian troops for more than a month following their Feb. 24 invasion of Ukraine. Local officials say more than 300 people were killed by Russian forces in Bucha alone, and around 50 of them were executed. Moscow denies the accusations.
According to Der Spiegel, the radio messages corresponded with known deaths. In one intercept, a soldier discusses shooting someone off their bicycle. A body was photographed lying next to a bicycle.
Spiegel added that there were additional sound recordings whose physical origin was harder to pinpoint, which it said suggested similar events had occurred in other Ukrainian cities.
Ukraine's government has accused Russia of genocide and war crimes. The Kremlin said on Tuesday that Western allegations Russian forces executed civilians in Bucha are a "monstrous forgery" meant to discredit the Russian army and justify new Western sanctions.
Russia casts the evidence of civilian executions as a cynical ploy by Ukraine and its Western backers, who Moscow says are gripped by discriminatory anti-Russian paranoia.
A German government spokesperson declined to comment on the Spiegel report.