IMMIGRATION officials have joined forces with their Canadian counterparts to stop hundreds of Sri Lankans with forged travel documents from using Hongkong as as a staging post. Thousands of Sri Lankans, most of them Tamils, try to illegally enter Canada each year, where immigration policies allow them to apply for residency once they land. Canadian police believe the groups organising the illegal documents and shipments of people are linked to the Liberation Tigers of Tamil Eelam, the largest group fighting for an independent homeland for the Tamils in the north of Sri Lanka. More than 100 Sri Lankans have been stopped at Kai Tak since January 1, transiting the territory with forged travel documents. This has already exceeded the total of 96 caught at the airport last year, most of whom were apprehended in transit after arriving from Singapore. ''We recognise this as a serious problem and the commission spends a good deal of time on it,'' said Mr Neil Reeder, spokesman for the Commission for Canada. ''The illegal transit through the territory of unproperly documented Sri Lankans is one of our major concerns.'' Hundreds of Sri Lankans are stopped by airline officials before they land in Hongkong and are deported to Colombo, but those who make it through Kai Tak usually head to Japan before flying to one of Canada's major airports. State-of-the-art equipment was being installed in the Commission for Canada yesterday as part of a campaign to stop what immigration officials see as a ''major problem''. The computerised Photophone system, also used by Interpol, the Royal Canadian Mounted Police and immigration authorities in Japan, the Netherlands and Britain, is the first of its type to be installed in Hongkong. ''Photophones are now being used by immigration authorities in Canada to increase security by verifying the validity of travel documents at ports of entry,'' said Ms Susan Mey, managing director of Info-Imaging Services, which supplied the unit. The system works by checking travel documents against the original copies. ''The Commission for Canada in Hongkong will be able to use their Photophone to check passports at Kai Tak international airport from their offices in Central without having to dispatch someone with specialised equipment,'' she said. While the quality of the fake documents is believed to have improved, some illegal passports still have correction fluid applied over original names and new photographs pasted over old ones. Last year, more than 1,000 Sri Lankans were stopped at immigration checkpoints around the world while another 1,000 were intercepted after arriving at Canadian airports on forged documents. In a recent report, Canadian police said ''organised groups involved in the smuggling of Sri Lankans [and Somalians] utilise visas which are either rented, bought or fabricated in Canada''. ''Upon arrival in Canada, the false documents are presented by the user who immediately claims refugee status.'' The police said people desperate to enter Canada and circumvent legal immigration procedures paid between C$5,000 (HK$30,800) and C$15,000 for fraudulent immigration documents, citizenship certificates and Canadian passports.