In one instance, Mr. Morris’s firm sold a home to an investor in California just days after it burned down. The case was settled recently, according to a court filing. The terms were not disclosed.

David Hensel, a lawyer for Mr. Morris, declined to comment.

Mr. Morris left Fox News in 2017 to sell investment advice full time. His company offered to connect clients with turnkey investment homes in Indianapolis, Detroit and other cities, then oversee renovations and hire local managers to collect rent. But customers soon complained that Morris Invest was taking their money and leaving them with dilapidated properties after renovations they paid for upfront were poorly done or not done at all.

The investigation by the F.B.I. and federal prosecutors in Newark began early this year after complaints about Morris Invest and Mr. Morris’s former business partner began to pile up with regulators in Indiana, in New Jersey and at the Federal Trade Commission. Its existence was only recently confirmed.

John Tompkins, a lawyer for Mr. Whalen, said his client “personally relates to the feelings and hardships of Clayton Morris’s victims who may have lost thousands of dollars in the individual properties they invested in.” He added that Mr. Morris had “also defrauded and deceived” his client.

Mr. Morris and his wife, Natali, moved their family to Portugal in July after selling their $1.4 million home in New Jersey. Ms. Morris, in a blog post explaining the family’s move, said Mr. Whalen had taken advantage of her husband. She also blamed the news media for putting a “disproportionate amount of blame” on her husband.