German companies played a larger role in the building of Syria's chemical weapons stockpile than was previously known, according to information provided by the world's chemical watchdog and reported by German media late on Wednesday.

The reports said that the between 1982-1993, German firms had made some 50 shipments of technologies and materials that could be used to produce chemical weapons.

Sueddeutsche Zeitung newspaper reported on Wednesday that the shipments included monitoring and control systems, pumps, ventilators, gas detectors and sulfuric acid that could be used to produce sarin. Also, German companies provided Syria with sketches for the construction of two installations capable of producing materials that are used in sarin production. However it is not clear if the plants were built.

The information was provided by the Organization for the Prohibition of Chemical Weapons had provided a list of firms to Germany based on information supplied to it by Syria.

The Organization for the Prohibition of Chemical Weapons had provided Germany with a list of firms based on information supplied to it by Syria. Subsequently, the German government has asked federal prosecutors to examine whether German firms broke the law by exporting equipment to Syria during the 1980s and early 1990s that may have helped the country to develop chemical weapons.

However, some deliveries were apparently made before goods required export licenses, or fell under later arms control laws.

The reports said that Russian, French and Chinese firms, and not only German companies, have been involved in helping Syria develop its chemical weapons program, but also

Last September the government published records showing Germany exported 111 metric tons of chemicals to Syria between 2002 and 2006 that could be used in the production of sarin gas. But it rejected suggestions from Left party politicians that it might have inadvertently contributed to the sarin attack in Syria last August, which resulted in the killing of hundreds of civilians.

Western governments blamed the lethal attack on President Bashar Assad, but the Syrian government said the weapons were unleashed by rebels fighting to topple him in a civil war.

The chemicals were classified as "dual use" under European Union law, meaning they could be used for either civil or military purposes. They require special export permits.

Arms exports are a sensitive issue in Germany because of its Nazi past and the role of its arms makers in fuelling 19th and 20th century wars. Modern chemical warfare was pioneered by the Germans on the battlefields of World War One.

Damascus agreed last year to destroy all chemical weapons facilities and surrender 1,300 metric tons of toxic agents to a joint OPCW/United Nations mission. It has until June 30 to eliminate its chemical weapons program completely.

The deal averted the threat of U.S. missile strikes to punish Damascus for an August 21 sarin gas attack that killed hundreds of people in the outskirts of the Syrian capital.

In signing the convention, Syria committed to providing full details about how it had developed its chemical weapons.

Open gallery view Danish soldier wears a protective mask during an emergency drill aboard a frigate escorting Syrian chemical arms shipments, January 2014. Credit: AP