Videos obtained by CNN suggest Taliban groups in Afghanistan have been receiving weapons from Russia.
Taliban groups in the north and west are shown using heavy machine guns they say were provided by Russian government sources. Experts told CNN the weapons were altered to make it impossible to determine their origin.
Afghan government spokesman Sediq Sediqi said the government has heard reports that Russia is aiding the Taliban.
"The Russians have said that they maintain contact with the Taliban, we have lots of other reports from other people they are arming the Taliban ... there is no smoke without fire," Sediqi said. "That's why our intelligence agencies are up to the job to find out what level of support that is to the Taliban."
U.S. generals had previously suggested Russia was arming the group.
In March, Gen. Joseph Votel, chief of U.S. Central Command, told a congressional committee that he believed the Russians were trying to gain influence in Afghanistan.
"I think it is fair to assume they may be providing some sort of support to (the Taliban) in terms of weapons or other things that may be there," he said.
Russian government officials have tried to debunk these claims and denied their involvement in the matter.