Zane Gbangbola died during a flood, and while an inquest ruled that his death was due to a petrol-based pump in the house, his family maintain is was due to gas from a landfill site.
Spelthorne Council have now passed a motion saying crucial evidence has been ignored.
Councillor Ian Beardsmore told the meeting that high levels of hydrogen cyanide were found the day he died, but the report was not accepted by the coroner.
They’ll now be writing to the Home Secretary and demanding a “Hillsborough level” investigation.