THREE firms have been struck off the Register of Companies because there were indications their activities undermined the territory's international commitments to curb the proliferation of chemical and biological weapons, the Security Branch has confirmed. The South China Morning Post revealed yesterday that three locally based companies with links to Russia, Austria and Australia were struck off in February amid allegations they helped China supply deadly nerve gas technology to Iran. The companies were dissolved on February 17 after a two-year probe by Hong Kong and American investigators. A day later, the US State Department imposed sanctions against the three, barring them from doing business in America and putting them under watch in relation to alleged proliferation of chemical and biological weapons. The Security Branch said yesterday: 'We can confirm that investigations undertaken in co-operation with the US authorities in several countries, including Hong Kong, into the activities of the three companies named in the US Federal Register provided strong indications that the companies were engaged in activities that undermined Hong Kong's international commitments to curb proliferation. 'A decision was therefore taken to de-register the companies in Hong Kong. This clearly underlines the Government's determination to support international efforts directed at preventing the spread of nuclear, chemical and biological warfare material.' The companies were Asian-Ways Ltd, WorldCo (Hong Kong) Ltd and Mainway International Ltd. It was revealed that the foreign operators of the companies had come to Hong Kong on several occasions to arrange the purchase of 'off the shelf' firms as fronts. The territory dissolved the three under section 360C of the Companies Ordinance, following an order by the Executive Council. That order followed the Secretary for Security finding them in breach of Section 8 of the Societies Ordinance, which allows for the shutting down of a 'society' if there is reason to believe its operation 'may be prejudicial to the security of Hong Kong or to public safety or public order'. A fourth company - Asian-Ways Holdings Ltd - was shut down at the same time and under the same powers. It was not put on the US Government watch list. Company records show that one man - an Australian living in New South Wales - is a shareholder or director in all four companies. They also list as directors or shareholders two Russian merchants - one in Austria and the other based in Moscow - a German merchant living in Austria and two Hong Kong-based merchants. Documents filed for Asian-Ways Holdings Ltd also name a Hong Kong-based engineer. The State Department said the ban on the companies exporting products to, or doing business in, the US was imposed under the Chemical and Biological Weapons Control and Warfare Elimination Act of 1991 and would last at least one year. The US had not made a definite determination that China itself had committed a sanctionable act in connection with the incidents.