An urgent probe has been launched into how the personal details of benefit claimants were disclosed to some Colchester householders.

The borough council is investigating the breach of personal data during the delivery of housing benefit notification letters to residents last week.

Bosses said the error would be “robustly” examined but did not reveal the nature of the disclosure.

The incident relates to a number of housing benefit notification letters received by residents during the early part of last week. However, council tax and business rates letters also sent in recent weeks were said to be unaffected.

The council said it was working closely with its main billing mailing supplier to identify every resident affected by the breach.

Each individual will then be contacted with an explanation, and all necessary steps taken to minimise any impact.

Colchester Borough Council’s head of business and resources, Paul Smith said: “The council takes extremely seriously that this data breach has occurred.

“I want to reassure all residents that we are taking immediate and robust action, working with our supplier to fully understand the reasons behind it and learn the necessary lessons to do all we can to prevent it happening again.”

Meanwhile, the Council has notified the Information Commissioner’s Office and will submit all required information as the investigation progresses.

Mr Smith said: “Many thousands of letters have correctly been issued in recent weeks but we apologise to residents who have been identified as affected.

“We will work to do everything possible to minimise the impact of this error on these customers.

“I urge any housing benefit recipient who has concerns to contact our customer services directly.”

Any resident receiving housing benefit, and who has concerns, is advised to contact the council directly at revenues.enquiries@colchester.gov.uk or on 01206 505336.