More than a gigabyte of leaked emails were released by a group of Ukrainian hackers from an account used by Putin's adviser Vladislav Surkov.
The cache published by the Ukrainian group CyberHunta reveals contacts between Surkov and the pro-Russia rebels fighting Ukrainian forces.
It also comes as the United States has accused Russia of coordinating the recent hacks of the Democratic party's emails to influence the outcome of the presidential election.
A senior US intelligence official told NBC News the US had 'no role' in the hack.