If you happen to be in central London this afternoon then you may be in with a chance of photographing a whale which has been spotted in the River Thames.

The mammal – believed to be a 5m long northern bottled-nosed whale – was last seen swimming past the Houses of Parliament.

Speaking to BBC News, Tom Howard-Vyne, who works for the London Eye on the south side of the river, said: ‘I saw it blow, it was a spout of water which sparkled in the air… an amazing site.’

It was first spotted in the river at 8.30 this morning by a man on a train.

At the time of writing a team of intrepid photographers from AP’s offices, which are located near the river, were heading off in search of a picture.

The BBC is urging anyone with photographs to email them to yourpics@bbc.co.uk or by MMS to 07725 100 100.