A deliberate fire started in the early hours of Sunday morning saw 100 tonnes of wood go up in smoke at a building site in Radwinter – just days after police warned there was a serious risk of vandalism and theft at the site.

Police said they had spoken to contractors and builders on Thursday, warning of the risk, after the site was broken into three weeks before.

Paula Foxall, 51, whose house is adjacent to the area on Old Roman Road, phoned the fire brigade at around 1.30am, after seeing 40 foot flames and pluming smoke from her bathroom window.

“It was only when I was in my bathroom getting ready for bed that I saw the fire through the trees and thought ‘Oh my God, what’s going on?’,” said Mrs Foxall, who had driven back from a party in London that night with her husband Frank.

“If we hadn’t come when we did, it could have been a hell of a lot worse, it was really scary, and so loud.

“I opened the window and the noise of it was just incredible. It was quite windy, so I didn’t know if any of the trees were going to catch alight, I was really quite concerned.”

Neighbours on the other side of the site said their cars were covered in ash during the incident – which they slept through “blissfully unaware”.

Firefighters worked through the night to tackle the blaze, started in a great mound of debris and wood which had been brought into the middle of the site. The crew brought the fire under control shortly before 6am, though it continued to smoke considerably for the next two days.

Builders who work on the site, being cleared for the development of three houses by Moody Homes, told the Reporter they thought the site had been broken into – possibly via the public footpath adjoining the land.

“When we turned up this morning there was a swivel chair on one side of the fire, as if some kid had been watching the blaze, like a film director,” said one foreman builder, who did not wish to be named.

“There’s a footpath directly alongside it, so they could have come in from there.”

When the site was broken into just three weeks before, with signs of the lock to the portacabin being forced, tea, coffee, a kettle, and a can of petrol were among the items stolen.

“The fact they didn’t take the expensive generator, which was just lying there, would indicate it was kids work,” the builder added.

Essex fire service said an investigation had concluded the fire was started deliberately. Essex police have not said whether the blaze is a suspected arson or not.

The force is appealing for witnesses and has asked anyone with information to call 101.