Camden Council has been ordered to overhaul procedures after a data protection blunder potentially endangered residents.

The Information Commissioner’s Office (ICO) has told the council to make “effective and robust” improvements following the mistake by its legal department in February.

The data protection watchdog launched an investigation after an alleged problem neighbour on a council estate in Somers Town was given the details of at least five people who had accused him of anti-social behaviour.

Three of them had only agreed to give evidence to the council, which was taking legal action against the tenant, on the condition that they were kept anonymous.

A spokesman for the ICO said: “The ICO wrote to the council and asked it to implement an effective and robust improvement plan that established how the incident occurred and drew lessons to prevent it from happening again.

“We also asked them to review their procedures to ensure appropriate technical and organisational measures were taken to prevent the unlawful processing or accidental loss of personal data.

“We asked the council to provide us with a copy of the improvement plan within three months, after which it will be assessed.

“If we are not satisfied with the improvement plan they provide, we may need to review the case and reopen our investigation.”

A spokesman for Camden Council said: “We welcome the recommendations from the ICO and are working with them to implement their recommendations to ensure that this administrative error does not occur again.”