A Mafia-connected online gambling ring placed $200 million in illegal horse-racing bets over the last five years and “doped” thoroughbreds for enhanced performance, according to federal prosecutors. Seventeen defendants were indicted at Manhattan federal court yesterday.

Members of the Uvari and Appelbaum families are accused of leading the ring and using threats of violence to collect gambling debts. Police and prosecutor say the ring was connected to the Genovese and Gambino crime families. Three of the 17 individuals charged are associates of the Gambino crime family.

Members would bet on up to $80,000 in a single day on races at several tracks throughout the country, including the Belmont and Aqueduct racetracks.

Members of the ring, known as the Uvari Group, were based at New York, New Jersey, Florida, Nevada, and New Hampshire. They used tax-protected facilities at the Isle of Man in the United Kingdom, Curacao at the Netherlands Antilles, Fargo, N. D., and the Tonkawa Indian Reservation in Oklahoma, according the U.S. Attorney’s office.

The ring was open only to “high rollers” like doctors and lawyers who put up at least $100,000 to become members, police investigators said.

Bail was set at $500,000 for David “Pebbles” Appelbaum, who was allegedly involved in every aspect of the business. His lawyer said Mr. Appelbaum’s business activities are legal.

“They’re foreign casinos that they bet through on behalf of a group of people,” said an attorney, Neal Hurwitz, who defended Mr. Appelbaum at his arraignment. “Is this illegal? I’m not so sure.”

Six of the defendants are first-of-kin relatives. Mr. Appelbaum’s son, Jonathan, and his wife, Linda, who own property at Ardsley in Westchester County and Las Vegas, were also indicted, as well as Gerald Uvari, 67, of Coconut Creek, Fla., his brother Cesare, 63, of Marlboro, N.J., and his son Anthony, 29, of Las Vegas. They are among 11 defendants who were arraigned yesterday on charges of gambling conspiracy.

Mrs. Appelbaum filed the losses of members as her own losses on her tax returns, receiving $250,000 in illicit returns, according to the prosecuting attorney Benjamin Gruenstein.

Gregory Martin, 36, of Long Island, is the son of a horse trainer who allegedly engaged in “horse doping” to artificially increase a thoroughbred’s performance. Bail was set at $100,000 for Mr. Martin yesterday.

Some, but not all, of the bettors were clued into the alleged doping, according to police. Prosecutors said that, in one instance on December, 18, 2003, at Belmont, a horse won a race after a tube was run into its stomach to suck out the animal’s gases and it was given performance-enhancing drugs.

Many of the defendants were seized at their homes yesterday morning. Defendant Marvin Meyerowetz was arrested at his Hackensack, N.J., home, where $500,000 in cash was confiscated, according to police.