Carillion, one of the UK's biggest construction firms, has been implicated in allegations surrounding the treatment of migrant workers in Qatar as it prepares to host the World Cup in 2022.
BBC news said it "uncovered worrying testimony about pay, housing conditions and safety standards from foreign workers" including some employed by subcontractors working for Wolverhampton-based Carillion.
The workers said they worked long hours for little pay while living in inhumane conditions. Their passports had been confiscated and recruiters were taking a large chunk of their wages to pay for living expenses.
Carillion has since launched in investigation into the claims which were initially aired on the BBC's flagship Newsnight programme.
The construction firm has been working on the Msheireb Downtown Doha project, which is a joint-venture costing around £400m.
It published the following statement on its website:
As a leading support services and construction company, Carillion sets best in class standards for our people’s health, safety and working conditions wherever we work.Carillion is deeply concerned and surprised by the claims made by Newsnight concerning one of our subcontractors and one of their sub-suppliers in the programme broadcast on the 8th December.We are conducting an immediate review of these claims to establish the position and take appropriate action.