ALBANY, N.Y. -- The New York State Racing and Wagering Board has begun investigating six winning Breeders' Cup wagers worth a total of $2.5 million, all made Saturday by one person at an upstate Off-Track Betting parlor.

According to Tuesday's Washington Post, the investigation involves a Ultra Pick Six bet that was allegedly placed after four of the races had been run, racing officials said.

''We started looking into this (Sunday), so we froze those tickets pending a review of the situation,'' Stacy Clifford, spokeswoman for the racing board, said Monday. ''There could be something here or there could be nothing here. Obviously it's a very important investigation and we want to make sure it's a thorough one.''

The six winning bets -- each worth $428,392 -- were apparently made through a telephone account with Catskill OTB, Clifford said. The Ultra Pick Six tickets were for Breeders' Cup World Thoroughbred Championships at Arlington Park in Illinois.

According to the Post, there is intense interest on Breeders' Cup day on the Ultra Pick Six, because of a huge potential payoff. Bettors try to pick the winners of six consecutive races -- which on Saturday included a 26-to-1 shot, a 13-to-1 shot and a 43-to-1 shot. There were six winning tickets -- all sold at Catskill OTB.

Ultra Pick Six wagering on Saturday totaled more than $4.5 million.

The investigation came at the request of the National Thoroughbred Racing Association and the Breeders' Cup Ltd.

According to reports, the successful bettor made a single selection in each of the first four races, and then used all the starters in each of the last two. Although the minimum betting unit is $2, he played for $12, giving him six tickets on each combination. The total investment was $1,152.

"The unusual nature of the winning wagers prompted the ... request for a further review" by the New York State Racing and Wagering Board, the Breeders' Cup said in a statement.

D.G. Van Clief, the organization's president, said, "Our obligation in this case clearly is to protect the customer and the integrity of the process."

''It was a lucky day for a lucky fan,'' Don Groth, president of Catskill OTB, told the Thoroughbred Times. ''We believe that's what it was. We hope that's what it was.''

According to the Post, Groth identified the winner as a 29-year-old Maryland resident. He said that his records indicate that the wager was placed before the Pick Six had begun.

Clifford said she didn't know how long the investigation would take. She declined to name the bettor.

Information from the Associated Press is included in this report