A seven-year-old boy who died after falling ill in a flood-hit town had suffered carbon monoxide poisoning.
Zane Gbangbola and his parents became ill at the family home in Thameside in Chertsey, Surrey, in February and were taken to hospital, where he later died.
An initial post-mortem examination into Zane's death proved inconclusive, but Surrey Police said today: "Further tests have now been completed by the pathologist who has given a result of carbon monoxide intoxication."
The statement added: "A petrol-driven pump was seized from inside the home address at the time of Zane's death and Surrey Police is conducting further inquiries to establish whether there is any liability or criminal offences in respect of the hire company who provided this equipment."
The incident happened during the floods which inundated the area earlier this year.
Police said an inquest into Zane's death will be held in due course by the Surrey Coroner.
Officers have met Zane's parents to update them on the post-mortem examination result, police said.
In the early hours of Saturday February 8, Zane, his father Kye Gbangbola and mother Nicole Lawler were all taken ill. An ambulance was called and all three were taken to hospital. Both Mr Gbangbola and his son had suffered cardiac arrests .
An initial post-mortem examination on the seven-year-old found "no clear cause of death".
Last month, company director Mr Gbangbola, who was left paralysed from the waist down following the incident, started legal action in a bid to find answers.