Mr. Nahmad’s lawyers, Benjamin Brafman and Paul Shechtman, say their client has done nothing wrong. Mr. Brafman declined to discuss his client’s secretly recorded conversations, which included one in which he speaks of using the family’s art business as a cover to move around illicit money.

In it, Mr. Nahmad advises a woman to wire $150,000 to the bank account of his father, David (who was not charged), suggesting she lie about the reason, saying, “You just be like, Oh yeah, I bought a, you know, Picasso drawing or something.”

Mr. Brafman said, “It is a mistake to draw any negative inference or conclusion about a case or a particular defendant based on isolated taped conversations taken out of context.” Among page after page of mundane conversations about gambling and recordings of Mr. Nahmad taking bets over his cellphone were glimpses of a strange world of greed, gamblers and two classes of bettors: Those who kept wagering and who, it seemed, never ran out of money; and those who kept wagering, though it seemed they had none.

Because several of the men accused of operating the gambling rings are related — a father, Vadim Trincher, and his two sons, Illya and Eugene — some of the wiretapped conversations have an oddly homespun feel to them, even as others revealed the thuggery and threats of violence some ring members used to pressure those who would not pay.

“Have the guy call my dad tmrw at 10 a.m. he will connect him to the guy in Moscow,” Eugene Trincher tells another man in a text message. Another time, a defendant in the case sends Eugene a text about a money pickup in Las Vegas: “Ur dad still need me to pick up cash in lv?”

Another man wrote to Illya to tell him that his father was cleaning up at a poker game at the Plaza in the early hours of one January morning, saying “Your dad is eating people up.” He added later: “Pops won a big pot this past half, don’t forget to remind him to tip the dealers, ha-ha!”

When Eugene Trincher picked up approximately $500,000 in cash from someone associated with an online gambling Web site, he brought it back to the family’s apartment in Trump Tower and his brother, speaking of the cash, later told their father:

“Dad, give it to Mom for a couple of days so she’ll give it to somebody else.”

The affidavits, which are used by prosecutors to persuade judges to sign orders authorizing wiretaps and searches, contain details of the investigation and excerpts from conversations recorded pursuant to earlier eavesdropping orders.