Army bomb disposal experts were called in after a suspicious package was found on an offshore platform near the Fife coast.
An area was cordoned off at Harbour Place in Burntisland as emergency services dealt with the incident.
Police Scotland said nobody had been hurt and said there was not believed to be any danger to those on the rig.
The item was found on a drilling rig off the coast of Methil at around 10.40pm on Monday. It is understood it was set to be brought to shore at Burntisland.
A team from the Royal Logistic Corps was at the scene on Tuesday afternoon.
Briggs Marine, whose premises were within the cordon, appeared to be operating as normal.
A spokeswoman for Police Scotland said: “We received a report following the discovery of an unknown package on a drilling rig at Methil.
“As a precaution, a cordon is currently in place at Burntisland harbour while the emergency services and explosive ordnance disposal are at the scene.
“There is currently not thought to be any danger to anybody on board the rig.”