Nairobi, Sept. 1 -- Immigration lawyers are seeing a surge in work as more Kenyans in the US fight to remain in the country amid the Donald Trump administration's crackdown on sham marriages-arrangements in which foreign nationals marry American citizens to obtain green cards.

The crackdown has raised the stakes for those accused of marriage fraud. Kenyans and other immigrants charged with conspiracy to commit marriage fraud face a maximum prison sentence of five years or a fine of up to Sh32.3 million, turning what was once seen by some as a shortcut to permanent residency into a potentially costly criminal case.

Some of the Kenyans and other Africans involved in the marriage scam paid from $35,000 (Sh4.5 million) to as much as $45,000...