The number of workers killed in Qatar during preparations for the World Cup was between "400 and 500", a drastically higher figure than previously announced, a Qatari official has admitted.

According to the Associated Press, quoted by Lusa, the statements by Hassan al-Thawadi, secretary-general of the Supreme Committee for Delivery and Legacy of Qatar, were made during an interview with British journalist Piers Morgan.

Al-Thawadi's comments could add to criticism from human rights groups about the cost to migrant workers of the country hosting the first World Cup in the Middle East, when 200 billion dollars were spent on stadiums, metro lines and new infrastructure needed for the tournament.

The Supreme Committee and the Qatari government have yet to respond to an AP request for comment on Al-Thawadi's statements today.

In the interview - excerpts of which have already been published by Piers Morgan on the internet - the British journalist asks Al-Thawadi: "What is the honest, totally realistic number of migrant workers who have died as a result of the work you are doing for the World Cup as a whole?".

"The estimate is around 400, between 400 and 500," said Al-Thawadi.

"I don't have an exact figure. That's something that's been discussed," he said.

However, this figure has not previously been discussed publicly. The Supreme Committee's reports dating from 2014 to the end of 2021 only include the number of deaths of workers involved in the construction and renovation of the stadiums that now host the World Cup.

The total number of deaths released by the Qatari government was 40. These figures include 37 that local authorities describe as non-work-related incidents, such as heart attacks, and three workplace incidents. In another report, the death of a worker due to the new coronavirus during the covid-19 pandemic is also reported separately.

Since FIFA awarded the tournament to Qatar in 2010, the country has taken some steps to overhaul employment practices. This included scrapping the so-called 'kafala' employment system, which tied workers to their employers, who could decide whether employees could leave their jobs or even the country.

Qatar also adopted a minimum monthly wage of 1,000 Qatari riyals (275 dollars or 265 euros) for workers and required food and housing allowances for employees who do not receive these benefits directly from their employers. It has also updated its safety rules for workers to prevent deaths.

"One death is one death too many. Pure and simple," Al-Thawadi added in the interview.

Activists have called on Doha to do more, especially when it comes to ensuring that workers are paid on time and are protected from abusive employers.

Al-Thawadi's comment also renews questions about the veracity of government and private company reports of worker injuries and deaths in the Persian Gulf states, whose buildings were constructed by workers from South Asian countries such as India, Pakistan and Sri Lanka.

Mustafa Qadri, executive director of Equidem Research, a labor consultancy that has published reports on the cost of construction for migrant workers, said he was surprised by al-Thawadi's remark.

"For him to come out now and say that there are hundreds [dead] is shocking. They have no idea what is happening," Qadri told AP.