The German government on Wednesday defended granting permits around a decade ago for exports to Syria of chemicals that can be used to make deadly sarin gas.
The economy ministry said the export licences were granted between 2002 and 2006 for shipments totalling more than 100 tonnes of chemicals for both military and civilian use.
They received the green light after "careful examination of all possible risks, including abuse and diversion threats in view of their possible uses in connection with chemical weapons," the ministry said.
Ministry sources said the chemicals were "classic dual-use" products that could also be used in the surface treatment of metals, fluorination of drinking water and the manufacture of toothpaste.
UN chemical weapons inspectors reported this week that banned chemical weapons were used on a large scale in the Syrian civil war, and that evidence showed sarin gas killed hundreds in an opposition-held area near Damascus on August 21.
The UN report did not say who used the sarin gas, though the Syrian opposition and its allies have blamed President Bashar al-Assad's troops. The United States claims more than 1,400 people died in the attack and has threatened to attack Assad's regime.
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The German ministry conceded that chemicals that could potentially be used to make sarin had been exported, responding to a question in parliament by the far-left Linke opposition party.
"In all these cases a plausible case was made for their civilian use," the ministry said. "The evaluation of all the available information before the permits were issued led to no evidence of military use that would have justified a refusal of the permission."
It added that the "government has no information to suggest the delivered goods have since then been used for anything other than the stated civilian purposes."
Linke party lawmaker Jan van Aken suggested that the government had been grossly irresponsible.
"I really can't believe it," he told ARD public television. "Germany over many years delivered more than 111 tons of chemicals with which one can produce sarin to Syria, a country known to be operating a chemical weapons programme."
The military threat against Syria's regime has eased after Russia and the United States agreed on a plan to put Syrian chemical arms under international control.
Syrian officials have denied using sarin gas and Russia said Wednesday Damascus had given it evidence that the rebels were behind the August 21 attack.