Experts say BN(O) passports are among the easiest to fake, helping to make the SAR a key human-smuggling port

EASY to alter, handed out to people who no longer need them, and with visa-free access to about 80 countries - the three million British National (Overseas) passports issued to Hong Kong residents by their former colonial masters have become the 'document of choice' for gangs smuggling thousands of mainland illegal immigrants around the world every year to destinations in North America, Europe and Australia.

British authorities are now upgrading the security of United Kingdom passports and have begun issuing new documents in a bid to beat forgers. A new model of the BN(O) passport, said to be virtually identical to normal British passports, is expected to be issued in October.

The Immigration Department says the BN(O) is the third-most popular forged travel document they find. Last month alone, 17 passports were spotted by officers checking passengers. That brings to 84 the number of the fake burgundy-coloured travel documents found in the first five months of this year. This compares with 351 forged mainland passports and 334 fake two-way permits. However, two-way permits can only be used for travel to Hong Kong, not internationally.

The human trafficking trade has come under heightened scrutiny since the corpses of 58 mainlanders trying to sneak into Britain were found inside a truck at the port of Dover on Monday.

Smugglers have been switching their routes from the favoured destinations of Canada and the United States to Western Europe over the past six months after a crackdown on North America's west coast, according to experts.

US and Canadian law enforcement efforts were stepped up following the discovery in January of three mainland men who had perished inside a stinking, canvas-covered cargo container crammed with 15 other people on a 16-day voyage from Hong Kong. More than 100 others were found in containers being unloaded in Seattle and Vancouver.