Nottinghamshire Fire Service has blamed an electrical fault for the blaze that ripped through four floors of County Hall.

Council workers and councillors were evacuated from the building shortly before midday on Thursday (July 28) when the fire took hold of the office used by Councillor Neil Clarke, cabinet member for transport.

The blaze, which began in the first-floor office, then spread to the second, third and fourth floors.

At its peak, fire crews from Nottinghamshire, Derbyshire and Leicestershire tackled the blaze using 12 pumps and two aerial ladders. The fire was extinguished by 6pm.

Speaking yesterday, Cllr Clarke told the Local Democracy Reporting Service that the fire – which gutted his office – was started by an electrical fault within the ceiling void.

He said he lost personal belongings including files and computers in the fire – and other offices in the Conservative Group's corridor had also been damaged.

The fire service has now finished its investigation – and confirmed the electrical fault was the cause. It also said all fire evacuation procedures and fire doors worked successfully.

Watch manager Tim Marston carried out the County Hall fire investigation alongside station manager Jim Dykes.

Mr Marston said: "The fire has been attributed to an accidental electrical cause, leading to the overheating of a lighting fixture and adjacent wiring within the ceiling void on the first floor of the building.

"The fact that the affected floor had well-fitting automatic fire doors, that functioned correctly, is a testimony as to why the most severe fire and radiated heat damage was contained to one area, leaving adjacent stairwells clear to aid evacuation.

"Our fire protection team will continue to support Nottinghamshire County Council with its recovery process as it looks to bring the building back to full use."

Speaking to the Local Democracy Reporting Service on Tuesday, Cllr Clarke added: "[My office is] pretty much burnt out. I've lost quite a lot of personal stuff, computers and files, and there's smoke damage to some of the other offices to varying degrees across the corridor.

"It's quite expensive and it's going to be a major job to get it right."

The ruling Conservative group is now expected to face disruption while alternative accommodation is found, with council leader Ben Bradley saying councillors won't be allowed back into their corridor "for quite some time".

The West Bridgford building was handed back to the authority on Monday, with a clean-up operation now underway and staff told to either work from home or from alternative council buildings.

Derek Higton, the council's director for place and communities, said: "We would like to thank Nottinghamshire Fire and Rescue Service for not only its swift response on the day, but also for how it has carried out the subsequent investigation into the fire since it broke out at County Hall on Thursday."