Bank account detail have been found near a motorway after they apparently fell out of a van.

The Prudential files concern investments worth millions of pounds and include cheques and other sensitive papers.

The documents were found by a driver on a roundabout by a sliproad for Junction 11 of the M4 near Reading.

They were being carried by DHL from a Prudential building in Reading to a storage facility in Essex.

Prudential has now reclaimed the box, and letters were being sent out to all the customers affected.

A spokesman said: "It was a delivery being made on our behalf to a secure storage facility in Essex and basically the DHL van and the box parted company at some stage during that journey.

"Protection of our customers' data is of paramount importance to us and we are contacting them immediately.

"The key thing is that none of those customers will suffer any financial loss as a result of this."

A spokesman for DHL added: "We take incidents of this nature extremely seriously. The driver responsible has been suspended pending a full review of the incident."

David Porter, head of security and risk at Detica, a group of intelligence and counter-fraud specialists, said of the error: "The flurry of stories about data loss in recent months is helping focus minds on the processes of managing and securing data.

"In this incident, it appears that we have the transfer of data from one secure site to another but that task has been outsourced and we don't know the level of security that was required of the contractor.

"It is no easy task for organisations to ensure that their own rigorous standards are upheld by their contractors.

"Fraudsters can thrive on lost data but fortunately the odds of it getting into the hands of a would-be criminal with appropriate levels of expertise are relatively small.

"Data loss has been happening for centuries. It's the volume, and the speed and the disguise which IT systems allow that now raise the risks of data loss."

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