ROYAL Mail in Belfast is raking in millions of pounds auctioning off items lost in the post to help meet running costs.
But bosses of the postal giant don't want you to know exactly how much they make from selling customers' mail - or the amount given to charity.
And they refuse to even discuss what happens to the massive bulk of items which do not go to auction.
The revelation comes after a retired teacher discovered that a set of antique bagpipes - which Royal Mail had lost - appeared for sale on internet site eBay.
Although the package was correctly labelled, it spent three months languishing in the national returns centre at Tomb Street in Belfast before being sold to online bidders.
The centre handles all returned parcels from throughout the UK which are deemed "undeliverable".
If no-one comes forward to claim an item within six months, it is put up for auction or goes to charity.
The company insists that the proceeds from auctions contribute to the upkeep of the returns centre.
But last night a senior Royal Mail employee in Belfast claimed: "The centre is an expense built into the cost of a stamp.
"The huge sums of money from the sale of undelivered parcels is a goldmine for Royal Mail, providing a constant stream of revenue.
"People are astonished this hasn't been raised before because charities see very little of it.
"Items auctioned raise millions - never mind the actual cash found in packages that also goes straight into company coffers.
"Other items that do not go for auction used to be put on sale at internal staff functions, but there was a crackdown last year and only a handful of people know what happens to them now."
He added: "This is something Postwatch need to look at because it is a so-called service, and, apart from handling costs, the vast bulk of this money should go to charity."
A spokesman for Royal Mail confirmed that around 75,000 undelivered items are auctioned off every year "with some going to charity".
He added: "The proceeds from auctioned items go towards the upkeep of the national returns centre, which costs about £10m-a-year to run.
"For commercial reasons, we do not disclose the figures for the amounts raised from auctions."