The family of a British construction worker who died while building one of Qatar's 2022 World Cup venues has demanded that a full independent inquiry into his death be carried out by a United Kingdom-based body. Zac Cox, 40, fell 39 metres to his death in January last year while working on the Khalifa International Stadium in Doha. Mr Cox was on a platform when his safety harness broke and he plunged to his death. A coroner's inquest in England found that Mr Cox died because the equipment he had been asked to use was "not fit for purpose". Hazel Mayes, Mr Cox's sister-in-law, spoke to <em>The National</em> about the frustration the family felt during the investigation process from both the Qatari authorities and Pfeifer, a contractor working on the stadium. "Our problem the whole time has been access to information. We've scraped around trying to get information and facts, and this has been very hard to come by," Ms Mayes said. "At the very beginning of this awful period for our family, they [Pfeifer] committed to giving us daily updates and significant quantities of information. "The daily updates were never forthcoming. The information that they have fed us was not insignificant, but it has not been a transparent process." <strong>_____________________</strong> <strong><a href="https://www.thenational.ae/world/mena/builder-zac-cox-a-kind-and-thoughtful-man-let-down-by-world-cup-2022-site-equipment-in-doha-1.708737">Builder Zac Cox a ‘kind and thoughtful man' let down by World Cup 2022 site equipment in Doha</a></strong> <strong><a href="https://www.thenational.ae/world/mena/worker-falsely-blamed-for-colleague-s-death-in-qatar-considers-lawsuit-1.702982">Worker falsely blamed for colleague’s death in Qatar considers lawsuit</a></strong> <strong>______________________</strong> Speaking about the Qatari authorities, Ms Mayes said: "We've had hardly any dealings with them whatsoever. Only since we've spoken out more publicly have they tried to be in contact with us, which I think is utterly disrespectful." One crucial piece of information, eventually submitted to the inquest, was an internal report prepared by the contractors, but never formally given to the family. The family obtained the report through unofficial channels and it found that lever hoists used by the contractors did not have up to date safety certificates and that the health-and-safety system had not been followed. Germany-based Pfeifer claimed that the report was not official because it was internal and therefore "not relevant". Ms Mayes said the report, which was completed within 11 days of the incident, "gives the most factual account of the event". "To say it is 'not relevant' is absolutely untrue," she added. The family have opted not to speak to the media about the case until now because they feared it might be detrimental to the ongoing case involving <a href="http://www.thenational.ae/world/mena/worker-falsely-blamed-for-colleague-s-death-in-qatar-considers-lawsuit-1.702982">Graham Vance, Mr Cox's co-worker who was falsely accused</a> by the Qatari authorities of causing Cox's death. Mr Vance, a South African, who had been working with Mr Cox when he fell, was arrested on the same day and was unable to leave Qatar for 11 months until the police investigation had concluded. He has since left Qatar and is considering a lawsuit. "We were initially reluctant to come forward because we had absolutely no desire to create any further pressure on Graham, who we have always believed to have been an innocent victim of this process," Ms Mayes explained. She said: "Knowing that he was wrongfully held out there in Qatar for us was deeply distressing. He had just witnessed the death of his colleague at close proximity and it must have been an absolutely awful 11 months for him." Ms Mayes and her family have called for a fully independent inquiry to be carried out into Mr Cox's death to prevent further deaths in building the Qatar World Cup stadiums. Mr Cox’s relatives have called on the UK-based Health and Safety Executive to be involved in such an inquiry. "The main thing for us is that the inquiry is impartial rather than procured on behalf of one of the parties that are playing a big role out there and we would have no confidence of the impartiality of that outcome," she said. "We believe that is the only way that we could reach some sort of sense that accountability has been assigned, and that processes can be improved so that no one else will meet the same fate as Zac."