The coastguard was involved in a six-hour overnight search off the water at St Andrews.
Police requested assistance just after 8pm on Monday with lifeboats from Broughty Ferry, coastguard teams from Dundee and St Andrews and a rescue helicopter sent to the scene.
It came after a report that a person may be in the water.
Data from the tracking website Flightradar24 showed the coastguard helicopter flying up and down the coast at St Andrews.
A coastguard aeroplane from Humberside also joined the search for a time.
However, they were later stood down after it was thought to be a false alarm with good intent.
A spokesperson for HM Coastguard said: “We received the alert at 8.15pm to assist police at East Sands beach in St Andrews.
“Lifeboats from Broughty Ferry station were launched.
“Coastguard officers from St Andrews and Dundee were also dispatched to assist police.
Search in St Andrews continued until 2.30am
“In addition, rescue helicopter 199 was sent to the scene.
“A search of the area continued throughout the evening.
“Officers were stood down at approximately 2.30am.”
A Police Scotland spokesperson said: “At around 8.10pm, police received a report of concern for a person believed to be in the water off the coast of East Sands, St Andrews.
“Extensive searches were carried out by officers and coastguard, however, there was no trace of anyone having been in the water and no further reports.”