Further tests have now been completed by the pathologist who has given a result of carbon monoxide intoxication.
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.
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The Number 91 was travelling from Trafalgar Square to Tottenham in north London when it came to an unexpected halt.
It didn't take long for the converted flower shop to be snapped up. 220,000 people looked at the advert on Zoopla.
Glen Hazel, who was an 11-year-old schoolboy, has a clear memory of the events of 1966.