The figures from the Ministry of Development Planning and Statistics (MDPS) revealed that 1.4 million people live in what the department officially designates as “labour camps”.
At the time of the survey, the official population was 2.4 million.
That works out at just over 58 per cent of the country’s population.
The overwhelming majority — 1.34 million — were male, the statistics found.
Since the census, Qatar’s population has grown further to just over 2.5 million.
The accommodation of migrant labourers working on Qatar’s numerous infrastructure projects has long been a contentious issue.
Qatar, which will host the football World Cup in 2022, has been condemned by human rights groups, including Amnesty International, for providing “squalid and cramped accommodation” for its large migrant workforce.
Last week, 11 people were killed and 12 injured when a fire ripped through a camp housing labourers working on a tourism project in the southwest of the country.
Qatar has responded to the criticism by building new workers’ housing complexes, including the $825 million “Labour City” south of the capital Doha, which incorporates shops, cinemas and a cricket stadium.
The complex can house up to 70,000 foreign workers and is one of seven workers’ “cities” being developed which will accommodate almost 260,000 people in total.
The population of gas-rich Qatar has soared over the past three decades as it has imported a huge migrant workforce to develop its infrastructure. In 1986, just 373,000 people lived in the emirate.