BBC Radio Manchester has been shown photos of letters in a bag - salvaged from the fire - that have been singed around the edges. Retrieved letters are being delivered - in some cases six months late - with a covering letter from the Royal Mail. A Royal Mail statement said: "Royal Mail is investigating a staff member from Eccles delivery office on the suspicion of withholding and destroying mail. "These investigations are ongoing and the worker has resigned from his post. "Royal Mail has a zero tolerance approach to any dishonesty and that stance is shared by the overwhelming majority of postmen and women, who are honest and hardworking and who do all they can to protect the mail and deliver it safely."