On a property near Tully, 27 cattle have been found dead and Mr Kerswell had been using the good old method of trial and error to come to a conclusion as to why this consignment of cattle bound for live export were dead.

The metal detector proved that the cattle were not shot - the instrument's radar detected no bullets - but helped the Mareeba policeman determine that the livestock were in fact killed by lightning. Police say there is clear evidence of a severe lightning strike with extensive damage to nearby trees.

The bolt of lightning ran down a tree under which the cattle were sheltering, and the current surged through the wet ground upon which they were standing causing immediate death.

The cattle had been dead for up to five weeks before the deaths were reported.