'UFO' spotted over London 2012 site

The 2012 Olympic Stadium - but what is above?

Here at BBC London we bring you updated views from the London 2012 site with two Olympic webcams.

One of the webcams is of the new 80,000 seater stadium and has been operating since June 2008.

The photo above shows a view from the morning of 10 May 2009 timed at 09.55.

The shape on the right of the picture shows something that appears to be hovering above the stadium.

Is the saucer shaped object just dust on the camera lens, a balloon or something else? Tell us what you think?

We found the photo after trawling through this year's images to produce a timelapse video. The object appears in 20 photos from 08.45 until 11.56. A selection of photos are below.

The 2012 Olympic Stadium, 10 May 2009

In the past we have found amazing sunsets, severe weather and even a spider that occasionally makes an appearance!

Our guess - probably dust or a cobweb on the lens but have you seen anything in the area? Let us know.