A badly-decomposed porpoise was found washed up at the beach at St Annes this morning.
Coastguard officers were called out to measure and official record the royal mammal from near the lifeboat station before it was collected by council staff.
The animal is understood to have been dead for around three weeks, and its death is not related to the oil spill currently affecting the Fylde coast, a spokesman said.
Concern has been voiced about the potential impact on marine and wildlife following the spill, which originated last Monday at an off-shore storage tanker in Liverpool Bay.
But experts leading the clean up have yet to link any animal death to the pollution incident.
A porpoise washed up last week was also found to have been dead for some time.