According to a representative of the Russian military in Syria, the commission has visited a hospital in Douma and questioned witnesses to investigate the alleged use of nerve agents.
The expert group has found no traces of chemical poisoning with chlorine or sarin.
Last week, several Syrian opposition online media outlets reported, citing militants that the Syrian Army had used chlorine in the town of Douma and killed up to 70 people.
Following the reports, a number of states, including the US, accused Damascus of staging the attack, while German Chancellor Angela Merkel said earlier in the day that evidence of the use of chemical weapons in Syria is "clear and explicit".
The Russian Reconciliation Center for Syria has categorically refuted the reports. The Center's representatives visited the place of the alleged attack and questioned local doctors, who said that they had not received individuals with symptoms of any chemical poisoning.