Popplewell wrote that the families of those tragically killed in the 1989 stadium disaster should ' move on ' and stop harbouring ' conspiracy theories ' .
Popplewell chaired the public inquiry into the 1985 fire at the Valley Parade stadium that killed 56 people .
Popplewell , who chaired the public inquiry into the 1985 fire at the Valley Parade stadium that killed 56 people , wrote that the families of those tragically killed in the 1989 stadium disaster should ' move on ' and stop harbouring ' conspiracy theories ' .