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 veterans agreed to submit an appeal to Fatou Bensouda, the prosecutor at The Hague-based court, over Russian civilians being used as private military contractors in hotspots around the globe. The conflict zones include Syria, Libya, sub-Saharan Africa and eastern Ukraine.

The Russian government officially does not acknowledge using 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

Concord Catering General Director Yevgeny Prigozhin, a target of the letter because o fhis support of using private military contractors

Dmitry Potapenko, a participant 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.

"There are more private military companies in Russia now," he said. "Unless we define the legal status of these people and unless we get rid of this official-level hypocrisy, the number of PMCs will not go down. Any state has special operations it tries to carry out. It's normal practice."

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