Qatar World Cup organizers have admitted that workers were exploited while contracted for FIFA's preparation tournaments in the Gulf State.

The acknowledgement of failings came after an investigation by Amnesty International which said security guards were forced to work in conditions it called "forced labor" by exceeding the 60-hour maximum work week and not having a day off for months or even years.

Qatar provided no details of the abuses that involved subcontractors working on the Club World Cup and Arab Cup in 2021.

"Three companies were found to be non-compliant across a number of areas," Qatar World Cup organizers said in a statement.

"These violations were completely unacceptable and led to a range of measures being enforced, including placing contractors on a watch-list or black-list to avoid them working on future projects -- including the FIFA World Cup -- before reporting said contractors to the Ministry of Labor for further investigation and punitive action."

The exploitation of workers continues in Qatar despite World Cup organizers saying it has introduced measures since 2014 -- four years after FIFA awarded it hosting rights -- to protect health and safety.