Yep, plenty, and tbf it's entirely logical. The people working at Yandex do not want find themselves dying of a nerve agent or polonium, which is a real and acute danger for people who displease the ruling regime.

https://hal.science/hal-03217497

https://euvsdisinfo.eu/yandex-from-tech-innovation-to-inform...

https://pmc.ncbi.nlm.nih.gov/articles/PMC10130930/

https://misinforeview.hks.harvard.edu/article/a-story-of-non...

If it's true just link to a first party example on the yandex site