AN international drug trafficker who plotted with a Macau tourist guide to smuggle more than six kilograms of heroin worth $5 million into Hong Kong was jailed for 24 years yesterday. Wong Ka-shun, 47, and Yim Chun-pong, 32, were arrested after a joint operation by Thai, Dutch and Hong Kong authorities. Tourist guide Yim was caught as he arrived at Kai Tak with 6.25 kg on July 6, 1992. He told police about a similar operation the previous month in which a stash of 'gift wrapped' heroin was hidden in the ceiling of a toilet at the airport, the High Court heard. The guide also claimed one of his accomplices had been transport worker Wong. A third trafficker has never been caught. Wong, who denied both conspiracies, was cleared of the first smuggling plot but convicted of the second. Prosecutor Joseph Yau told how Yim collected the heroin in Bangkok and took it to Phuket in a cunning scheme to bypass Thai Customs. After meeting Wong, the pair re-wrapped the drugs in gift paper and made their way separately to the airport, each carrying a blue holdall. Yim, who was carrying the heroin, went to the domestic departures lounge, where there was no Customs check, to board an internal flight to Bangkok. Wong, who pretended not to know Yim, sat down next to him and swapped holdalls. Yim then went through Customs to the international departure lounge with the dummy bag to catch the same Bangkok flight, which was continuing to Hong Kong. But as the pair boarded the aircraft they exchanged bags again. Mr Yau said Wong got off the plane at Bangkok, leaving Yim to continue to Hong Kong with the drugs. But the tourist guide was stopped at Kai Tak as he walked through Customs. Passing sentence, Deputy Judge Pang told Wong the plot had involved 'careful and elaborate planning'. Yim, who admitted his role in the second operation and gave evidence against Wong, will be sentenced at a later date. He was not charged with the first conspiracy.