Merseyside Police arrested three people on Friday after a drone was spotted being flown near to Aintree racecourse.
The police said three men - a pilot and two spotters - aged 54, 52 and 35 were arrested on Red Rum Close in Aintree on suspicion of offences under the Air Navigation Order. The drone was also seized.
A search of a vehicle linked to one of the men resulted in a large quantity of cash also being seized, police said. Information has been submitted to the Civil Aviation Authority.
Chief Superintendent Paul White said: "We have a team of officers and partners who are monitoring any drone activity around Aintree racecourse to establish if any offences have been committed.
"On this occasion they detected breaches in legislation which resulted in the three men being arrested and the drone being seized.
"Merseyside Police will continue to seek ways to combat the illegal use of drones to keep the communities of Merseyside safe."
The issue of drone use around racecourses has been going on for some time. It is believed images from drones are used to give in-running punters an unfair advantage on betting exchanges, because the streamed pictures may be a few seconds ahead of TV channels.
