Insurers moved closer to recovering their multi-million pound losses from the Buncefield oil depot explosion after the latest Health and Safety Executive (HSE) report concluded that mechanical failures and human error were partly to blame.

Norwich Union (NU) said it now expected operators at the Hemel Hempstead site to accept legal responsibility for the incident last December.

Paul Redington, property claims manager at NU, said: "Even in the absence of an admission of liability from Hertfordshire Oil Storage Ltd (HOSL) or other parties within the perimeter, we would expect a process to be put in place which would now enable early repayment of valid subrogated claims, that is money we have paid out to our policy holders."

He said legal discussions were ongoing with the site owners.