What is thought to be a bowhead whale, usually found in Arctic waters, has been spotted swimming off the Dutch coast.

The whale was spotted swimming off the waters of Zeeland by passersby Wilma Bronke and Ingrid Pul on Monday evening, who filmed the giant mammal on their mobile phones.

A bowhead whale has been spotted several times off the Belgian coast in the past few days and experts say it could be the same animal. A similar sighting was made earlier in Cornwall, England.

‘It would seem to be an adult animal of some 20 metres long,’ Albert Dijkstra of the sea mammal help centre Eerste Hulp bij Zeezoogdieren Zuid told local broadcaster Omroep Zeeland. ‘If it is the same whale as spotted off Belgium, it may have something hanging from its tail – rope or nets or something. That would not be good.’

Although whales do sometimes visit Dutch coastal waters, a bowhead has never before been spotted.