Sort out the fire claim or face a damages bill of up to £75m, Center Parcs' owners are understood to have threatened Marsh.
Sources said DB Capital Partners, a subsidiary of Deutsche Bank, issued the warning after the holiday park suffered a multi-million pound fire in April.
Insurance Times reported last week that AXA Corporate Insurance, the lead insurer on the risk, was understood to have reserved its right to void the policy due to alleged non-disclosure by the broker, believed to be Marsh.
The disagreement was believed to have stemmed from a risk survey by Marsh's Birmingham office that did not disclose problems with the centre's roof linings and partition walls.
Now DB Capital Partners are understood to have threatened to bring a professional indemnity claim worth between £50m and £75m against Marsh if it did not sort out the difficulties with the claim.
It is understood that Marsh is self-insured. The broker would not comment on the allegations, citing client confidentiality.
Centre Parcs said that it did not comment on any of its commercial activities.
Sources told Insurance Times that the fire was caused by work carried out with hot tools on the centre's rubber membrane roof, which was being replaced with PVC membrane.
The tools ignited the polystyrene lining below the membrane. Sandwich panels were not involved.
The April accident was the second serious fire to hit Center Parcs, following the complete destruction of its De Eemhof centre in the Netherlands in May 2000.
Center Parcs' then-owner, brewing giant Scottish & Newcastle, never released the final figure for the Dutch damage, which some pundits reckoned to be £60m.
The centre had to be closed for rebuilding.The cause of the De Eemhof fire was not established, but the incident held up Scottish & Newcastle's sale of the holiday group to DB Capital Partners for several months.
Industry observers said Scottish & Newcastle became more attractive to insurers after it shed the Center Parcs group.
The April fire in Suffolk started in the centre's kitchen block and spread to the main plaza area, where many of the centre's facilities were located.
