Migrant workers, mostly from South or Southeast Asia, suffer "alarming" levels of exploitation, including non-payment of wages and hazardous working conditions as they toil to ready World Cup infrastructure, a new Amnesty report said.

Suhas Chakma, director of New Delhi-based Asian Centre for Human Rights, echoed Amnesty's conclusions in its own report Monday, saying treatment of workers in the world's wealthiest nation per capita was "inhuman".

There has been an explosion in poverty-stricken migrants heading to Qatar where a construction boom is underway to ready the tiny gas-rich nation for the World Cup.

The preparations provide "an opportunity to expose the treatment of migrant workers by a rich nation", Chakma said, adding countries which support human rights "should boycott the event".

Fifa has faced huge criticism from rights groups since selecting Qatar to host the 2022 World Cup.

Qatar, which rejects claims of slavery-style conditions on its building sites, promised to include the Amnesty report in an inquiry it has already launched while FIFA said human rights must be respected.

C.R. Abrar, a leading Bangladeshi migrant expert, said all nations sending workers to Qatar should pressure Doha to "fast-track" labor reforms.

Amnesty said its researchers had heard one construction firm manager use the term "animals" to describe migrant workers while a worker told the watchdog that "Nepalis are treated like cattle".

It said "the onus" was on Qatar to change its legislation and to enforce worker protections.

Abuses were systematic under a sponsorship system that "affords unscrupulous employers powers to exploit their employees, not least of which is the ability to prevent workers leaving the country".

Meenakshi Ganguly, South Asia director of Human Rights Watch, said migrant workers in Qatar "risk serious exploitation and abuse" and called on FIFA to tell construction companies to uphold "international labor standards".

NJF/NJF