Vijay Ganapathy, from law firm Leigh Day, who is representing the Gbangbola family, said: "We welcome this full post-mortem report, which will form part of the information provided to the coroner when the full inquest into Zane's death takes place.

"We will continue to work with the police with their investigations into the causes of this tragedy and who was responsible.

"We await further information provided by other agencies following their investigations, as many questions still remain unanswered into what toxins were present within the property on the night
of Zane's death."

The father of a seven-year-old boy  who died in floods in Surrey has said he believes the authorities are trying to stop him finding out what happened.

Zane Gbangbola, from Chertsey, died in hospital in February. His father, Kye, remains paralysed from the waist down.

The family's lawyers say it was an "apparent chemical poisoning" possibly 
caused by contaminated floodwater.

 Surrey County Council said it would not be appropriate to comment on the cause of death at this stage.

The Gbangbolas' home in Thameside was flooded for weeks in January and February when the River Thames burst its banks.

Zane and his parents were taken to hospital on 8 February after being taken ill. Both father and son suffered cardiac arrests.

Nearby homes were evacuated and 15 people were taken to hospital as a precaution.
 
Solicitors Leigh  Day are now investigating whether the family's house was affected by  hydrogen cyanide from a former landfill site nearby.

They claim the colourless gas hydrogen cyanide, which has in the past been linked to historic landfill sites, was found by the fire and rescue team called to the house. 

Surrey Fire and Rescue Service has not commented to the BBC.

 "I am broken, emotionally as well as physically," said company director Mr Gbangbola.

 "I don't worry too much about myself - it would be wrong considering what happened to my son.

 "Zane was always a happy, fun, extremely talented special ray of sunshine."

A post-mortem examination found no clear cause for Zane's death and an inquest was opened and adjourned pending the results of toxicology tests.

The local authority said on 28 April that the Abbeyfields site near the family home was a landscaped lake as a result of mineral excavation and had not been used for landfill. It warned against spreading panic among local residents.

But a historic  landfill site is shown on the Environment Agency's website.

Mr Gbangbola said: "It seems as though the various agencies involved are actively working against providing any information and that should cause some concern as to the trust the public should have."

Surrey County Council said in a statement: "Police are investigating this sad case and are waiting on the results of tests so it would not be appropriate to speculate on the cause of death until they have them."

Public Health England said in May: "Public Health England has not identified any evidence suggesting there is a public health risk, or hazard, to  neighbouring properties."