Friends and family this morning filled every chair at Woking Coroner’s Court for a pre-inquest review into the death.
About 10 people from the Truth About Zane campaign group gathered at the front of the court before the hearing with placards demanding answers. They wore red and orange flowers, Zane’s favourite, to symbolise the campaign.
In February of last year Zane, who attended St George’s Junior School, Weybridge, was taken to hospital with his mother Nicole Lawler, 37, and father Kye Gbangbola, 48, after being overcome by fumes when the basement of their £1m riverside property in Chertsey filled with floodwater.
His parents were rushed to hospital, where his father Kye Gbangbola would be left a paraplegic due to the effects of hydrogen cyanide poisoning.
Kye, along with Zane’s mum Nicole Lawler, have always maintained their son was killed due to that same deadly gas being released through water contaminated by a former landfill site behind their Thameside home.
Senior Surrey coroner Richard Travers said although a number of experts recently-consulted had come down on the side of carbon monoxide as the "most probable" cause of death, they were not able to be more certain than that.
He said: "There is evidence that hydrogen cyanide was detected at the scene."
However, a pre-inquest hearing at Woking Coroner’s Court on Friday heard Zane’s blood contained only 8% of the toxic gas - fatal levels are more than 50%. Blood levels below 30% is not toxic to humans and people living in any metropolitan area 12% to 15% is normal.
The family’s lawyer, Leslie Thomas QC, said at the hearing: “Can I remind you in this case [that] no carbon monoxide was found at the property. It was tested for and none was found.
"The only evidence of noxious gas that was detected at the property was hydrogen cyanide.”
The court heard how doctors at St Peter’s Hospital had conducted the wrong tests on Zane’s body for hydrogen cyanide poisoning.
“One of the issues in this case is the test for hydrogen cyanide has to be done very timely,” said Mr Thomas.
“There’s an issue whether or not the correct tests were done.
“When this issue should have been at the forefront of those doing the testing, they carried out the wrong tests.
“That in itself is another issue we say this inquest should be investigating.”
Representing Spelthorne Borough Council, barrister Ivor Collett argued only one reading from the fire brigade had shown hydrogen cyanide was present at the property, and said the device used could give a false reading.
“If we stick to the medical evidence of the child, and the feature is we have a very clear picture,” he said.
"Of course, we understand the suspicion of the family and know that it comes from the [hydrogen cyanide] reading. No-one can criticise the family for their suspicion.
"What you don’t have is any evidence at all, medically, of the presence, real or not, of cyanide being a component in the death of the child.”
This was superseded when the pre-inquest review was provided with one of the medical records that shows Kye is diagnosed 'Paraplegic due to Hydrogen Cyanide poisoning.
The pre-inquest review heard how in 2010 the Environment Agency (EA) had "gas-proofed" a lock keeper’s wooden shed it owned, adjacent to the Gbangbolas' home, when it found there was "moderate risk to human health through water from the gravel pit behind". The key context is the 'Moderate' was read out twice by Mr Thomas to mean 'Death and serious harm'
Mr Thomas said: “If the EA was aware of the risks from this land to the extent to protect its own building, should they have notified others and its immediate neighbours?
"You see how immediate Zane’s property is to the wooden lock keeper’s shed.”
But Mr Collett said the protective membrane was a condition of a planning application approved by Spelthorne Borough Council and the risk test was based on assumption.
“The planning condition of such a membrane is standard for any property in a certain distance of a landfill site,” he said.
“The reason for that, frankly, is that it is cheaper to impose as a standard condition than to require testing of the land.
“It’s entirely uninteresting and non-sinister when you look into it.”
On the 28th April 2014 in an email sent by Surrey County Council it states "Think carefully about spreading panic among local residents" in an official statement they went on to say "Abbeyfields is a landscaped lake area as a result of mineral excavation and has never been a landfill site"
In a statement released after the pre-inquest review, Kye and Nicole said it was an important step towards revealing the truth about what they believed happened to Zane.
“We now hope for a full and proper investigation into his death,” they said.
“We are grateful to our legal team for their work so far. We should never lose sight that this is about a little seven-year-old boy, Zane Gbangbola, who died needlessly.
“The Truth About Zane campaign has been arguing that the care of people and public protection is paramount.
“Today Zane should be enjoying his last day of school before the summer holidays but instead we’ve had to endure a pre-inquest hearing into his death.”
Further pre-inquest review hearings were set for October 5 and December 7 this year.
A four-week inquest will open on January 18 2016, with the court not sitting on February 8 or 9 - the anniversary of Zane’s death.