Amnesty International says the number of people detained in Nepal since the king suspended civil liberties has surpassed 3,000.
The London-based organization says its estimate is based on reports from local human rights groups. It says the detainees include political and human rights activists, trade unionists and journalists. The group also said it has detailed reports of detainees being tortured.
Amnesty's report comes as Nepal's foreign minister defended King Gyanendra's decision to seize power on the eve of an international summit in Jakarta where the monarch aims to seek support for his power takeover.
No government comment on Amnesty's report was immediately available in Kathmandu.
The monarch has said he fired the government because Nepal's squabbling political parties were not able to end the country's nine-year-old Maoist insurgency.
Some information for this report provided by AFP and Reuters.