Firefighters have blamed workmen at Center Parcs in Elveden for causing the £100m blaze, according to reports.
An initial investigation by the Suffolk Fire Service into the fire which destroyed the leisure park on 4 April said contractors working on a roof near the catering area had caused the disaster.
AXA, Cornhill Insurance and other insurers will face the £100m loss. It is understood AXA and Cornhill will share the first £50m layer.
About 3,500 holidaymakers and 400 staff were evacuated from the Center Parcs site, after the fire broke out at 10.30am in the kitchen area.
Loss adjuster Cunningham Lindsey is handling the claim and is expected to publish its own findings by the end of the week.
