TNT says unclear if it ever had data

AMSTERDAM (Reuters) - Dutch mail company TNT said there was no way of verifying if a shipment with personal data of 25 million Britons and believed lost was actually sent through the mail system it operates.

TNT runs an internal mail system for HM Revenue and Customs, the tax authority, that carries up to 100,000 mail items each night.

Chancellor Alistair Darling told parliament on Tuesday that two discs containing information on 25 million Britons had disappeared after being sent through the mail system.

TNT said the system offered the option for the sender to choose a service that offers full track and trace of a shipment, but for the shipment in question, that option was not selected.

"General mail does not carry a track and trace mechanism and hence it has been impossible, in this instance, to conduct an audit to identify if the item entered the system," the company said.

TNT said it was cooperating fully with the tax authority and the Metropolitan Police in the investigation into the missing computer discs.

TNT shares were down 3.3 percent at 25.62 euros by 3:40 p.m.

"It's embarrassing, it was sensitive mail," ING analyst Axel Funhoff said.

Funhoff said it was unlikely, however, that TNT would lose customers as a result.