Some $7 million was stolen late Saturday at Caymanas Park, The Gleaner reported.
Police want to know how two men got past two electronically activated doors into a cash processing room with an internal locking mechanism that can be activated by people in the room.
Men equipped with knives and guns robbed two employees in the room about 8:30 p.m.
Investigators have released little information about the robbery. However, a source told the newspaper there were no video, electronic entry data or eyewitness accounts of anyone entering or leaving the area.
The track's stable area lost its security detail earlier this year due to budget constraints. A trainer was shot and killed Friday near his barn in the area.
The last attempt to rob Caymanas Park was more than 30 years ago, in April 1978. One of the suspects in that robbery was shot and killed by police. A police officer also was killed.