'Russia's envoy to the UN has handed over evidence which indicates Syrian rebels used sarin gas in an attack in March.'
Vitaly Churkin said Russian experts had been to the scene of an attack at Khan al-Assal near Aleppo and had gathered firsthand evidence.
Syria's government has refused to let a UN inspection team into the country, but this week invited UN officials for talks on launching an investigation.
Mr Churkin said the Russian inquiry had "established" that rebel forces had fired a Bashar 3 missile at the town, killing 26 people, including 16 troops.
"The results of the analysis clearly indicate that the ordinance used in Khan al-Assal was not industrially manufactured and was filled with sarin," Mr Churkin said.
"There is every reason to believe that it was the armed opposition fighters who used chemical weapons in Khan al-Assal."'