The crash killed 78 people, and authorities in Galicia said 95 people were still in hospital, 32 of them, including four children, in a serious condition.

The source at QBE said the firm has not yet produced an estimated insured loss from the accident as the cause of the crash remains unclear.

According to previous statements, QBE says its exposure to any single public event is limited to $50 million under its reinsurance arrangements, whereby insurers sell risk to other parties to hedge their own liability.

A QBE spokesman in Sydney said he could not immediately comment on the matter.

Allianz's Spanish unit Allianz Seguros released a statement on Thursday confirming it underwrote the Renfe policy and that it had implemented an action plan and sent a team of experts to the accident site.

While the insured loss for physical damage to infrastructure and property is likely to be resolved quickly, compensation claims by victims and their families could take years due to lengthy legal processes.

Local businesses may also claim compensation for loss of revenue caused by disruption to the rail network.

Payouts will depend on liabilities, whether the accident was the fault of the driver or whether there is a case for corporate negligence on the basis the train should have had fail-safe mechanisms in place to limit speed.