A leading Qatari official has admitted for the first time that hundreds of migrant workers died building the 2022 World Cup stadiums and other infrastructure.

Qatar has vehemently denied accusations of thousands of unexplained deaths among its large migrant worker community, who were brought to the Gulf state mostly from impoverished parts of south Asia over the past 12 years to build lavish stadiums and infrastructure for the four-week tournament.

The previous line insisted by Qatar officials was that 40 workers had died building the World Cup, 37 of which were “non-work incidents” meaning only three supposedly occurred as a result of poor working conditions.

However, in an interview with Piers Morgan, Hassan al-Thawadi, the secretary-general of Qatar’s Supreme Committee for Delivery and Legacy, put the number of worker deaths for the tournament “between 400 and 500” for the first time, a drastically higher figure than any other previously offered by Doha.

The comment threatened to reinvigorate criticism by human rights groups over the toll of hosting the Middle East’s first World Cup for the migrant labour that built around £200bn worth of stadiums, metro lines and new infrastructure needed for the tournament.

• The Independent report