Georgina Heap, 16, took the photograph on her iPhone on Friday evening. The ring was seen in the sky above Leamington Spa, near Warwick castle
* Circle remained in Warwickshire sky for three minutes and then vanished

* Georgina Heap, who took photo, said it is 'weirdest' thing she's ever seen

* UFO expert said he believed the circle could be a swarm of insects

* No fire in the area on Friday evening and no meteorological reason given

Weather experts have been baffled by a black ring which appeared in the sky above Leamington Spa on Friday evening.

Schoolgirl Georgina Heap was playing tennis with her mother Jo Heap when she looked up at the sky near Warwick castle and saw a mysterious black ring.

She photographed the circle on her iPhone but so far, no one can explain the origin of the strange black mark.

The ring remained in the sky for around three minutes before disappearing completely.

The circle resembles a giant smoke ring but Warwickshire Fire and Rescue service said that there had been no reports of fire at the time of the sighting.

The Met Office said that the ring did not appear to be weather-related.

Nick Pope, an expert on UFOs and a previous government adviser on unexplained phenomena, said he believed the circle to be 'organic'.

He said: 'It's a truly bizarre image. It looks like a smoke ring, but I can't see where it could have come from.

'Other alternatives would include some sort of unusual meteorological phenomenon.

'One other possibility is that the shape is made up of millions of bees or other insects, but I've never heard of insects behaving in this way before, so if this is the explanation, it's a real-life X-File.'

Georgina Heap took the picture of the strange black ring on her iPhone. The 16-year-old described the sighting as 'the weirdest thing I have ever seen'
Miss Heap, who is studying for her GCSEs, described the circle as 'the weirdest thing I have ever seen'.

She said: 'I looked up at it and thought 'what the hell?', it was amazing.

'It was just floating there like a cloud and then it disappeared. It wasn't birds either.

'There were about ten of us who stopped what we were doing and watched.'