Qatar has confirmed it is holding two British human rights workers in Doha who had gone missing a week ago while investigating the conditions of Nepalese migrant labourers.

Krishna Upadhyaya and Ghimire Gundev, who worked for the Global Network for Rights and Development (GNRD), disappeared after complaining of harassment by the police.

A statement on Saturday by Qatar's ministry of foreign affairs said the men were being investigated for "violating the law of the land" and that security forces had treated the men in accordance with international human rights law.

British consular officials had visited Upadhyaya and Gundev and checked on their well being, the statement added.

"Krishna Upadhyaya and Ghimire Gundev, who were detained by the security authorities in Qatar on the August 31, are under investigation for violating the law of the land," the statement said.

"Security services followed all the right procedures with the two men and that they were treated with humanity in detention in accordance to the international human rights law, in compliance with the Constitution and the federal laws in Qatar."

There is an ongoing communication between the Qatari ministry of foreign affairs and the security services on one end and the British foreign affairs office on another end."

The men's families have appealed for their immediate release.

Upadhyaya and Gundev were working on a report on Nepalese migrant workers, according to a statement issued by Upadhyaya's family.

Earlier this year, Qatar unveiled plans to improve workplace safety, housing and pay conditions for expatriate workers.