WASHINGTON — After a relatively slow start to his career as a consultant and lobbyist, J. Dennis Hastert, the former speaker of the House of Representatives, became very busy in 2010. He was traveling to spots including Singapore and Montreal, meeting with clients about ventures as varied as futures trading and Formula One racing.

He also made an unusual request to one of his business associates: to find a financial adviser who could come up with a plan for an annuity that would generate a substantial cash payout each year. According to the associate, J. David John, the former speaker also asked that the adviser not be told of Mr. Hastert’s involvement.

The request came just a few weeks before Mr. Hastert, according to charges in a federal indictment, made his first payment to a man known as “Individual A” in what was to be a total of $3.5 million. The money, two people briefed on an F.B.I. investigation of Mr. Hastert said, was paid to prevent the man from publicly saying Mr. Hastert sexually abused him decades ago, when Mr. Hastert was a high school teacher and wrestling coach in Yorkville, Ill.

“I did not think much about it at the time, but looking back at it, it does seem strange,” Mr. John said. “He just said he needed to generate some cash.”