Allotments 4 All

I've got a problem with my 2nd early crop - Kestrel. I've posted a couple of images in my gallery to show the trouble. Basically some have brown spots under the skin and when they're cut the centres are brown, if left the potato Will rot completely. The crop was dug around a month ago. Any ideas what the problem is?
Thanks
Paul

The Potato Council website is great for identifying potato problems.  I had a quick look and internal browning looks the closest to your image:

http://www.potato.org.uk/department/knowledge_transfer/pests_and_diseases/ref.html?item=40

You can search all the pests, diseases and disorders here:

http://www.potato.org.uk/department/knowledge_transfer/pests_and_diseases/index.html?menu_pos=resources

Thanks for the reply, may have been caused by the very hot temperatures in June followed by a wet July. I haven't had the problem before so hopefully just a one off.
Paul