Dolphin spotted in the River Thames near Putney Bridge

The common dolphin was seen multiple times from late morning on Thursday, and was described as appearing to be “struggling with the tide”.

It had not been spotted again by Friday afternoon, but Julia Cable – operations director at British Divers Marine Life Rescue – said if it is still in the river over the weekend, passers-by are likely to spot it.

British Divers Marine Life Rescue was monitoring the dolphin and asked for people to get in touch if they see it over the coming days.

Ms Cable said: “It was still in the area throughout the evening but its behaviour wasn’t really changing so we didn’t continue monitoring it too late. It’s too far really for a dolphin to be up the river. We do get them up there, this was a solitary one. It wasn’t really moving very far, it did appear to be struggling with the tide.”

Ms Cable said the rescue is not sure where the dolphin is now as there were no sightings of it on Friday.

She added: “Our hope is that it’s found its way to a more sensible location out towards Thames Estuary.”

If the dolphin is still in the river over the weekend the rescue is likely to hear about it, Ms Cable said, as she urged people to stay away from it.

“There’s no way we can actually physically move it unless it were to strand,” she said. “All we can do is monitor it, check its behaviour and do our best to ensure everybody out on the river is aware that the dolphin is there and that they keep away from it.

“The worst thing is if people start going up to it, it could disorient it more. They’re used to being out in open water, with all of the noise on the river going on, for an animal it’s very confusing.”