Azerbaijan has been pushing back against Russian dominance in the Caucasus region, seeking closer ties with Turkey and Israel.

Deaths in custody, media offices raided, and beaten and bloodied suspects paraded in court — relations between Russia and Azerbaijan, once considered close, have sharply deteriorated in recent days amid a series of high-profile incidents.

Azerbaijan's Prosecutor General has now launched a criminal case accusing Russian police of torturing and deliberately killing the brothers. A post-mortem conducted in Azerbaijan found they died from "post-traumatic" shock after being severely beaten in custody.