AN investigation has been launched after a memory stick containing the bank details of more than 5,000 council workers was lost.

Redcar and Cleveland Borough Council today instigated emergency procedures after the computer data containing the highly personal information could not be found prior to the monthly payroll process.

Senior council staff immediately began working on a widespread information exercise to alert all staff and members, whose information was included on the data stick, as well as contacting their trade unions.

They were given advice on how they could ensure that the information was not misused, including calling their banks, and an emergency helpline was set up to deal with queries.

Meanwhile, council employees hunted high and low for the 4ins computer equipment - which contained part of the back-up system for the authority's payroll system.

However, the search was finally called off this afternoon after the stick was discovered safe and secure at Eston Town Hall.

How and why it got there, no one fully understood last night.

A council spokesman said the memory stick had wrongly been moved from its usual safe place of keeping.

He said a search of the council premises at Eston led to the discovery of the memory stick in a locked container - news which council chief executive Amanda Skelton described as a "great relief".

"As soon as it became clear that the memory stick was not in the secure area where it is normally stored we recognised the potential seriousness of the situation," she said.

"The data on the stick included financial and banking details of around 5,400 people and was not encrypted.

"Obviously, we are all enormously relieved that the item has been found - and that it was, in reality, always under lock and key in our premises. But, that does not reduce the serious nature of the issues raised, especially in relation to our information and security systems.

"What we will now be doing is continuing the investigation already underway to ascertain the sequences of events which led to the memory stick not being in the secure area where it is normally held and the lessons we can learn to improve our procedures and implement the strongest possible security arrangements to safeguard personal information."

Eve Cole, Unison branch secretary, speaking while the memory stick was still missing, called for an inquiry. She said it should never have been allowed to have been lost in the first place.

She said: "Unison has called for an immediate and thorough investigation into how this was allowed to happen and asked that an urgent review of the council's security systems takes place."