Bettors who wagered on Maximum Security in the Kentucky Derby only to see the colt get disqualified for interference will receive refunds.

Twinspires.com, Churchill Downs’ online wagering service, tweeted that it will give back up to $10 to anyone who bet on Maximum Security to win in Saturday's Derby.

The company said $6,212,046 was bet on the colt to win. Maximum Security also had $1,495,408 bet to place and $1,272,082 wagered to show, so the disqualification cost those bettors about $9 million.

Officials cited Maximum Security for interference and the colt became the first Kentucky Derby winner to be disqualified for violating a state regulation that penalizes horses for impeding the path of another in a race.

Stewards, who supervise the outcome of horse races, referenced Section 12 of rule 810 KAR1:016. The rule calls for disqualification if “a leading horse or any other horse in a race swerves or is ridden to either side so as to interfere with, intimidate, or impede any other horse or jockey.” Stewards determined that Maximum Security interfered with the path of several horses as the field of 19 rounded the final turn in Saturday’s race.

Maximum Security crossed the line first by 1-3/4 lengths before two jockeys filed objections against the horse for interference. Stewards took 22 minutes before overturning the finish and elevating Country House to first while dropping Maximum Security to 17th.

Maximum Security co-owner Gary West strongly disagreed with the ruling and said he is considering several options, which could include appealing the stewards' decision.

Country House, a 65-1 shot, paid $132.40, $56.60 and $24.60.

Twinspires.com says $520,907 was wagered on Country House to win.

A $2 exacta wager — involving horses finishing first and second — paid $3,009.60. A $1 superfecta bet — involving the first four horses — returned $51,400.10.

Churchill Downs said wagering on the Kentucky Derby increased 10% to a record $165.5 million, surpassing the old mark of $149.9 million set last year. This year’s wagering included $4.1 million bet in Japan, the first time the Derby was offered for wagering in that country. Master Fencer, the first Japan-bred to run in the Derby, was sixth.

The track said wagering from all sources on the 14-race card totaled a record $250.9 million, up 11% over last year's total of $225.7 million.

The attendance of 150,729 was down 4% compared with last year, with the forecast of all-day rain keeping fans away, although the heaviest rain didn't fall until about an hour before the Derby was run.