Findings compiled from a range of government sources showed on average 12 migrant workers from Sri Lanka, India, Pakistan, Nepal and Bangladesh have died each week since December 2010.
The Guardian report cited an expert saying it was likely many of these migrants were working on preparations for the 2022 World Cup.
Qatar has engaged in a vast construction programme, including building seven stadiums, a new airport, and a new city, in order to accommodate the global event.
Amnesty has frequently condemned the state for using and abusing migrant workers to prepare for the World Cup.
A recent report by the human rights watchdog termed the event Qatar’s “world cup of shame” and pointed to extortionate recruitment fees, appalling living conditions and delayed salaries as evidence of migrant exploitation.
The Guardian report claims thousands of workers from the five south Asian states have died in unexplained or dubious circumstances – often listed as “natural deaths” – while working in Qatar in the last ten years.
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Data seen by the Guardian shows 69 per cent of deaths among Indian, Nepali and Bangladeshi workers were listed as natural deaths, with that number rising to 80 per cent among Indians alone.
These natural deaths often relate to acute heart or respiratory failure but could also be in part caused by Qatar’s intense summer heat, which a 2019 report revealed was a factor in many migrant worker deaths in the country.
Other causes of death were listed as “multiple blunt injuries due to a fall from height; asphyxia due to hanging; undetermined cause of death due to decomposition”, the Guardian reported.
Human Rights Watch (HRW) has repeatedly called on Qatar to amend laws which hinder autopsies and forensic investigations into sudden or unexplained deaths of migrant workers.
A 2014 report by Qatari lawyers recommended the same, but the government has failed to reform laws on autopsies.
The Guardian report warned the real death toll is likely to be significantly higher than 6,500, as data on the number of deaths that occurred in the final months of 2020 are not included.
The findings also do not reveal the number of deaths of workers from other countries which send large numbers of migrants to Qatar, such as the Philippines and Kenya.
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