Doha: Britain said it was investigating on Thursday after two British researchers were reported detained in Qatar while probing the working conditions of migrants building infrastructure for the 2022 football World Cup.

“We are aware of reports that two British nationals have been detained in Qatar and we are investigating,” a spokesperson for the British embassy in Doha said.

The Norway-based Global Network for Rights and Development said on Wednesday that two British staff — Krishna Upadhyaya and Ghimire Gundev — had disappeared in the Qatari capital after complaining of being followed by police.

The pair had been carrying out follow-up research on the working conditions of migrant labourers in Qatar after the authorities promised a raft of reforms to address an international outcry over their working conditions as the emirate prepares to host football’s premier tournament.

Upadhyaya had sent a text message to managers complaining that they were “being harassed and followed by Qatari police,” the rights group said.

It demanded “immediate cooperation from Qatari authorities to fully disclose the whereabouts and current situation” of its researcher and photographer.

“In the event that its employees are subjected to any kind of physical or psychological harm, GNRD is prepared to take all necessary legal action,” it warned.

Qatar gave undertakings earlier this year to improve workplace safety, housing, and pay and conditions for its huge expatriate workforce after world football governing body Fifa came under huge pressure from rights groups to review its decision to award the emirate the 2022 World Cup.