Claims from the fire at the Momart art storage warehouse will be “substantial”, said Hiscox fine art underwriter Robert Read.

He confirmed the insurer was heavily involved in the case and predicted the total value of the eventual claims would be “tens of millions”.

The exact loss is not known, as adjusters have not yet been allowed on site.

GAB Robins confirmed it had been appointed as adjusters for the building damage at the Momart warehouse.

The fire at the Momart warehouse in Leyton, East London, broke out in the early hours of Monday morning. Firefighters were still damping down the blaze on Tuesday evening.

Read said lists were being compiled of which pieces were being stored at the facility, but that until access was granted to the site no accurate estimation of the total loss could be determined.

“It will take two or three days to work out what was in the warehouse. In addition, we need to establish if the art was insured and what the insurance arrangements were,” said Read.

Neil Doherty, fine art loss adjuster with Clement Doherty, said a number of collectors, dealers and galleries would be involved in the claim. He said collectors would either have arranged their cover individually or gone through Momart.

Doherty confirmed that Hiscox and AXA Art had already instructed his company to act on the loss.

Doherty said firefighters had informed interested parties that the damage to the art looked extremely bad.

“There is no question that the claim is going to be very serious. Momart is coming up with a list of art stored at the facility, including paintings. These will have been totally destroyed.”

Doherty pointed out that the fire brigade had been pumping water into the site for two days, compounding damage to the canvases already done by the fire.

“Some of the bronzes may have survived, but it is impossible to say what the final cost of the fire will be,” he added.

Market sources have indicated that Lloyd's managing agency Ascot Underwriting is the insurer of Charles Saatchi's art collection, which included some of the works believed to have been destroyed by the fire.