Investigations have revealed that personal data was infringed in a cyber attack that struck Gateshead Council in the early hours of 8 January.
The local authority said it was contacting those affected, but admitted it could discover more breaches. It told residents it would contact them directly if it discovered their data was at risk.
Gateshead said the incident was contained due to the ‘robust’ security checks it had in place, and the council is now operating as normal.
The attack is being investigated by the North East Regional Organised Crime Unit, and the Information Commissioner's Office (ICO) is also liaising with the council.
Gateshead’s strategic director for corporate services and governance, Mike Barker, said: ‘As investigations continue there is a possibility of further issues arising, and we will work to mitigate this should that be the case.
‘Investigations so far have not indicated there is any further damage caused, but we need to be open to the possibility.’
