A mysterious 'tadpole shaped UFO' has been spotted trailing black smoke over the English channel in bizarre new footage.

The video was filmed by an Irish marketing manager during a Ryanair flight from Dublin to Paris last week.

It shows the unidentified craft as a black mass against the sunrise with a long tail of dark smoke stretching behind it.

A passenger on a flight from Dublin to Paris spotted the strange tadpole shape in the sky

In the short clip the tadpole shape appears to be moving very slowly above the clouds.

The 29-year-old passenger, who asked not to be identified, said the UFO had been dashing around in circles moments before he filmed it.

'I was just looking out the window mindlessly,' he said. 'Then I saw something moving around rapidly.

'Before I captured it on video, the UFO was rapidly moving around in circles. It was very strange.

'When it stopped I took my phone out to record it, as it was staying pretty still.'

It's unclear exactly where the plane was when the footage was captured, but the person filming estimates it was over the English channel.

'I've never seen any thing like that ever,' he said. 'It was like a big black tadpole in the sky.

The unidentified black shape can be seen above the clouds and sunrise. The 29-year-old man who spotted it said moments before he started filming the 'UFO was rapidly moving in circles'

'I just thought it was some weather balloon or contrails from a plane at first.

'What made me think that it was something more was the strange movements it was doing just before I recorded it.

'My knowledge on what devices might be in the skies is very limited, but this moved like a space craft you would see in the movies.

'I've never seen any thing like it ever. I mean, maybe there is a logical answer but I've been on many flights and never seen anything like it.'

The images emerge at a time when UFO sightings are in a global decline, with both the National UFO Reporting Center and the Mutual UFO Network noting a drop in reports.

The Ministry of Defence (MoD) used to maintain a team to investigate UFO sightings, however the taskforce was axed as part of a wider series of cuts in 2009.