The European Commission last month launched an investigation into lost airline luggage, voicing concern over the scale of the problem.
Last year 32.8 million pieces of luggage were mishandled by airlines around the world. In 2007 the figure was even higher, with 42.4 million bags mishandled, of which 1.28 million were never returned to the owners.
So what happens to unclaimed luggage?
Most airlines will allow three months for the owner to be found. If after that time the luggage remains unclaimed it is sent to an auction house.
There are a number of auction houses across Britain which accept lost luggage. The bags, cases and their contents are usually sold together as one lot. The proceeds of the auctions are mostly donated to charities.In the United States the Unclaimed Baggage Centre is one of the world's largest lost luggage auction centres.
It is located in Scottsboro, Alabama and handles over one million lost luggage items each year brought in from all over the world.
Around 60 per cent of the items are clothing with the rest being a mixture of electronic goods, jewellery, sports equipment and books, as well as the bags and cases it all arrived in.
Some of the more unusual items found in unclaimed luggage at the centre include a parachute, Egyptian artefacts dating back to 1,500 BC and a guidance system for an F16 fighter jet.
Once uncovered amongst the unclaimed bags and cases, items of high value such as the US Navy's guidance system are usually traced back to the original owners by the centre.
Australian laws changed
In Australia the federal government recently changed the laws relating to compensation for lost air luggage.
Australian travellers will now be covered by the Montreal Convention, allowing for fairer compensation on lost items and removing compensation caps.