not on deeds

When my parents bought their home in 1971 there was nothing stated on the deeds&#160; that was a mine outlet in the back garden .Forward&#160; &#160;40yrs&#160; Coal board turn up to check it ,he&#160; wasn't sure exactly&#160; were it was pointed to a area&#160; just asked if we had notice any movement in the ground.<br> I have now been told that the house is only worth half the value because of the shaft.&#160;<br> Just wondering if the Coal board should fill the shaft&#160;

Beryl - it's legal advice you need here with regards what rights and more you/the Coal Board have re the mine outlet and impact on your land/property&#160;