Moscow( CNN) A forum representing Russian military veterans took an unusual step Sunday by voting to ask the International Criminal Court to probe the Russian government's use of private military contractors in deployments abroad.

The Russian government officially does not acknowledge use private military contractors to advance foreign policy, and mercenary activity is prohibited by law. But earlier this year, after US airstrikes killed and injured dozens of Russian military contractors in Syria, the families of some of the dead began to come forward, creating a public-relations conundrum for the Kremlin.

Dmitry Potapenko, its participation in the veteran's forum, said the market for private military companies in Russia has grown significantly over the past few years. But, he said, it exists in a “legal gray area” as long as the government refuses to acknowledge their activities.