New investor lawsuits are emerging amid the wreckage of an investment boom in life-insurance policies that spectacularly collapsed.

The suits involve the secondary market in life policies, which boomed from 2004 to 2008 as thousands of old people sought to make fast cash by taking out multimillion-dollar policies on their own lives to sell to investors. Tens of billions of dollars worth of insurance changed hands. Under the deals, the investors pay the premiums until the insured person dies, at which point they collect the...