Mrs Winkworth, speaking to the Citizen the day after Wednesday night’s blaze, explained it wasn’t the loss of the 6m by 3m caravan (pictured) itself that upset her, but the loss of what was inside.

She had been using the caravan, which was outside her home on the A47 Fen Road, as a storage space for personal belongings and irreplaceable items including paintings by her grandad, Fred Read, who died 11 years ago. The paintings featured scenes from Spain and Italy, and had been exhibited in Spain. All of them are now lost.

The drama unfolded at around 11.30pm when Mrs Winkworth decided to turn in for the night, when she thinks she heard a noise from the front garden. She looked outside, but saw nothing, so she went upstairs to read in her bedroom.

“I was only reading for a couple of seconds when I looked at the window and thought ‘what’s all that flashing outside?’” said Mrs Winkworth, adding: “I looked and the caravan was ablaze.”

A passing motorist spotted the flames, called the fire brigade and helped Mrs Winkworth, who has only been living there for less than a year, get away from her home. But in the confusion, she forgot to say thank you to her mystery saviour.

She added: “The man phoned the fire brigade and he helped me past the fire and then he waited until the police arrived. I don’t know who it was, but I would like to say thank you to them.”

The fire was so severe, both lanes of the A47 were closed for a couple of hours to allow firefighters from March and Wisbech, who were called at around 11.45pm, to tackle the blaze.

They arrived to discover the caravan was well alight and there was a further hazard from two gas cylinders.

Firefighters wearing breathing apparatus used one jet and two hose reels to keep the cylinders cool and extinguish the fire.

Tony Raine, Watch Manager at March Fire Station, warned of the dangers of arson, and said: “Thankfully the fire did not spread, but those responsible could not have been certain of this.”

Police are appealing for witnesses to the incident to come forward. Anyone with information is asked to call them on 0845-4564564 or Crimestoppers, anonymously, on 0800-555111.

The wreckage of Karen Winkworth’s caravan is pictured after the blaze.

Photo: 08AF07649