Apple tree pest??

An acquaintance with a holiday home has a problem with one of his apple trees. Something has scratched away at the bark & made lots of holes in the trunk & larger boughs. Part of the tree is alive & producing fruit but the part affected by the 'pest' is dead. Does anyone know what could be causing this. Having surfed the net I'm wondering if it is the flathead apple tree borer.

I've got photos but don't know how to upload them.

Send the photos to me at sscbristol@yahoo.co.uk and I will upload them for you.

Done, thanks.

Photos added to original post  

Ta muchly