Migrant labourers at a stadium under construction for the 2022 World Cup in Qatar went unpaid for several months, rights group Amnesty revealed on Thursday, raising questions about worker protection efforts.

Around a hundred workers at the flagship Al-Bayt stadium have yet to be paid outstanding wages in full, the organisation said following a months-long investigation.

Workers at Qatar Meta Coats (QMC), sub-contracted to help build the distinctive tent-like ground 50 kilometres north of Doha, went unpaid for up to seven months according to Amnesty.

Some received partial payments on June 7.

"The problems faced by QMC workers were well-known to Qatar's Ministry of Labour and the country's World Cup organising body for nearly a year, but compensation only began after Amnesty International shared the findings of its investigation with these bodies," Amnesty wrote.

It spoke to numerous workers from South East Asia and Africa employed by QMC who said they had also faced other abuses that included being charged banned recruitment fees.

Those interviewed told researchers that all of the QMC workforce at the 60,000-capacity Al-Bayt venue were affected -- around 100 workers.

"Every day we are asking but they are telling us 'we are having a shortage of money'. They tell us they are trying their best," one of the unpaid workers told Amnesty.

In a letter to Amnesty, the tournament's Qatari organisers said they were made aware of the unpaid salaries in July 2019 after the issue was flagged in worker welfare interviews.

"Since that time, we have been working to find a solution," it wrote.

QMC had been banned from 2022 projects and the financially distressed company was recently sold to new owners, the correspondence added.

Qatari authorities have taken numerous steps to protect workers including the creation of an electronic Wage Protection System meant to detect unpaid salaries.

However, the effectiveness of the WPS has been mixed with numerous high profile cases of major contractors failing to pay.

Workers went on strike -- illegal under Qatari law -- in August 2019 over unpaid wages at one now defunct contractor, while last month rare street protests erupted over outstanding salaries.

In both cases officials stepped in quickly following the direct action and media attention, ensuring payments and taking legal action against the defaulters. 

While wealthy Qatar is one of the few countries forecast to run a budget surplus in 2020, coronavirus has hit many sectors of the economy.

Energy production, hospitality and aviation have been particularly hard hit with major employers like Qatar Airways and Qatar Petroleum warning of major redundancies. 

Feature image courtesy: AFP / Giuseppe Cacace