REDCAR and Cleveland Council over estimated the costs of a major cyber attack on the authority, it has emerged.

The council, in a report to its cabinet last August, said the incident in February 2020 had cost more than £10m.

But six months later this figure was reduced to £8.7m as a result of a financial impact assessment, the main reductions being to forecast staffing costs, “bad debt” charges and IT costs.

In April this year members of the council’s resources scrutiny committee demanded more information on the financial aspects of the attack, which rendered computer networks used by staff and the council’s website inoperative for a period.

A briefing note for members provided by way of an update, which included the new figure, said the task of quantifying the financial impact had been difficult.

It said early estimates were based on a set of mitigating actions and recovery solutions “predicated on worst case scenarios”.

Earlier this year the Government agreed to provide a grant of £3.68m as financial support for the authority after a process of negotiation lasting several months, with the council having to provide evidence of the impact of the computer hack, thought to have originated from abroad.

The opposition Labour group on the authority said the money, which came with a number of conditions, had fallen short of what was required, but council leader Mary Lanigan said the offer was “unprecedented” with Middlesbrough South and East Cleveland Conservative MP Simon Clarke describing it as “exceptionally generous”.