What is believed to be a whale has been spotted in the River Liffey near the opening to Dublin Bay.

The sighting was reported at lunchtime today at the Stena Line berth in Dublin Port.

The animal is estimated to be 20 foot in length.

Jimmy Murray who works in the area said it was a very unusual occurrence.

He says it is rare enough to see a basking shark in the area, but he has never seen a whale before so far up the river.

He said the whale was most probably feeding in the area and will likely head out to sea as the tide ebbs.

In a post on its Facebook page, the Irish Whale and Dolphin Group said: "While it could be a minke (whale), it could as easily be any of a suite of whales such as a juvenile fin or sei whale or even a northern bottlenose whale.

"So best to wait till we have more facts or video evidence before making any pronouncments on its species."

Additional reporting Philip Bromwell