DD came running in the house to say there was an ostrich sized egg in the hen house. So I went out to look and there was an egg which must have been 4 times a normal egg size. It had a bit of a crack in one end though and was a bit wet and DD dropped it on the floor as she picked it up.
When it cracked there was another fully formed egg (normal size) complete with shell inside it. Both eggs were immediatly eaten by the excited chickens so no photos unfortunately. I think it could have been a world record though.