Emergency services were called after a person, believed to be a man, was seen on the M9 standing on the bridge over the River Carron, near the Kelpies, Falkirk, at about 5.40pm on Friday.
There were concerns the person had entered the water after they were seen acting in a strange way.
Police and coastguard were among the emergency services called to assist with the search, which went on until about 9pm.
One witness said at the time of the incident: “There is a lot of police and fire engines near the Kelpies, roughly where the canal flows out to the River Forth between Grangemouth and Skinflats.”
Another witness who was driving at the time of the search said emergency services had blocked off one lane on the M9 as they gathered to help with the search and that traffic was moving slowly in the area.
At about 9.45pm, about four hours after the search, Police Scotland released a statement saying: “We have now concluded searches.
"While we have not traced the person involved we do not currently believe that they entered the water.
"We would like to thank those who called with information to assist with our enquiries.”
A coastguard spokeswoman said: “Just before 6pm today (April 2) Police Scotland requested the assistance of the South Queensferry and Kinghorn Coastguard Rescue Teams and the search and rescue helicopter from Prestwick to help with a search in Grangemouth.”
If anyone sees a person(s) in distress they are urged to contact Police Scotland on 101.