Qatari authorities have confirmed they are holding two British researchers who are investigating the 2022 World Cup facilities, which is linked with a scandal over poor working conditions and dozens of deaths of foreign workers.

Krishna Upadhyaya and Ghimire Gundev, who work for the Norway-based Global Network for Rights and Development (GNRD), were detained in Doha on August 31.

"All of the actions that have been taken against the two Britons are consistent with principles of human rights enshrined in the constitution," read the statement released by the Qatari QNA news agency on Sunday.

It was added that the two researchers are “being interrogated” and that the reason behind the detainment is “violations” of emigration laws.

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GNRD posted on its website that Upadhyaya had reached out to his family, saying, "I am well, I have been well looked after and I will be home soon.” He said that the reasons behind their arrest were “problems with paperwork.”

On Wednesday, however, GNRD stated that its employees disappeared after complaining of being followed and “harassed” by security forces.

A UK embassy spokesperson told AFP that they were “providing consular assistance” for the two, but did not disclose any details.

Amnesty International has voiced concern over the researchers’ "enforced disappearance," describing it as “extremely worrying”. The human rights organization stated that the two simply went missing after checking out of their hotel in the capital, Doha.

Upadhyaya’s wife, Sarita Poudyal, told The Guardian that she was “feeling very sad.”

“The Qataris need to send him back as soon as possible and we need to know the reason why this has happened. I think they don’t want the news about the way they treat migrant workers to reach the outside world,” she added.

The researchers were carrying out an independent probe into the conditions of migrant workers – after the Qatari government had pledged to ensure the situation improves.

Qatar is preparing to be the first Arab host of the World Cup, which will take place in 2022. The news about ‘Qatar slaves’ appeared for the first time in The Guardian last September; the daily revealed fatalities among migrant workers at the construction facilities due to overheating and dehydration. The paper also reported some workers hadn’t been paid, or had had their IDs confiscated among other numerous rights violations.

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The report was followed by an international uproar and calls to transfer the World Cup from the country.

To calm things down, Qatar issued a decree in July banning mid-day outdoor work in the summer heat, specifically between 11:30 am and 3:00 pm from mid-June until the end of August, the hottest months in the country. Companies were required to establish bank accounts for foreign workers and pay wages electronically within a week of the due date – or face sanctions. An electronic complaint system was also set up, and the authorities pledged to build housing to accommodate up to 150,000 workers.