Even London’s finest have been left puzzled by a mysterious creature spotted lurking in the River Thames.

Camera footage, first shared on YouTube by user Penn Plate last month but only picked up by media channels this week, appears to briefly show two dark humps in the river before they submerge under water.

The video, which has been just 30 seconds long but has been shared more than 1,870,000 times, was taken from a cable car on the Emirates Air Line with the strange sight appearing just off the Silvertown and Canning Town area.

The footage has been creating all kinds of speculation, including whether it was simply a whale or might in fact be the Loch Ness Monster on holiday.

Pc Kevin Buss, of Canning Town South ward, said: “I’ve never seen anything like it before and I’ve been here for around five years. No clue what it is, no one in office can understand either, so will be keeping an eye on the docks now.”