NEW YORK (CBSNewYork) — In New York, a horse is the only animal that can legally be raced for gambling purposes.

However, People for the Ethical Treatment of Animals released a report Monday documenting what they call undeniable evidence of illegal pigeon racing following a 15-month investigation that spanned five states.

The animal advocacy group claims pigeon racing brings in $15 million a year in illegal gambling and that only 40 percent of the birds that are raced survive.

EXTRA: PETA’s Pigeon Racing Investigation

PETA claims the birds are raised in captivity and when they are taken states away and let loose to fly home in the long-distance races, many fall prey to predators, starve or die in poor weather.

The report alleges that in one race in Queens, only four out of 213 birds returned.

“More than 60 percent of the birds won’t return from a typical race.” General Council to PETA, Jeff Kerr, told 1010 WINS. “Those who do manage to make it back but who aren’t fast enough to earn money are often killed by suffocation, drowning, neck-breaking or decapitation in a process the racers call ‘culling.'”

Investigators went undercover and collected evidence to prove illegalities in pigeon racing, according to PETA.

Kerr said investigators gathered video evidence of betting sheets and boards and even followed trucks that carried pigeons across state lines to videotape the release.

WATCH: Video Footage Collected During PETA’s Investigation

The report claims the biggest pigeon race in the Northeast, the World Trade Center Memorial Race, is run by the Bronx Homing Pigeon Club.

PETA claims they secretly dole out hundreds of thousands of dollars for winning bets. The club insists there is no gambling involved, adding that trophies are awarded to the winners.

“This is illegal gambling that crosses interstate lines,” Kerr said, adding that the practice violates both federal and state law. “We’re hopeful that the authorities and the jurisdictions will take this seriously and prosecute these crimes and bring those people to justice.”

PETA plans to submit their report to several law enforcement agencies, including the FBI and NYPD.

Sound off on this story below…