VANCOUVER, British Columbia — In the tightly knit world of Vancouver’s wealthy Chinese immigrants, Paul Se Hui Oei stood out for his ties to some of Canada’s most powerful politicians and his mastery of cultivating guanxi, or personal relationships, that attracted legions of Chinese clients eager for his assistance in gaining a legal foothold in Canada.

But behind closed doors, the authorities say, Mr. Oei, a prominent immigration consultant and philanthropist, ran an elaborate fraud scheme, pocketing nearly $6 million from investors, including many Chinese citizens led to believe their investment would help them secure permanent residency in Canada. Instead, the authorities say, he spent the money on luxury cars, beauty pageants and donations to the British Columbia Liberal Party.

“Everything he said were lies,” said Chen Wei, a Chinese immigrant who testified earlier this year in a case against Mr. Oei before a British Columbia Securities Commission panel. Mr. Chen’s family invested one million Canadian dollars ($782,000) in Mr. Oei’s project, according to hearing transcripts.

The case is part of a pattern, experts say, of problems with Canada’s immigration programs, which, like the United States, set aside coveted residency permits for foreign investors. Some also say it underscores a troubling flaw in the Canadian justice system, which often allows white-collar criminals to walk away with little more than a slap on the wrist.