The audit had been launched after human rights group Sherpa had alleged that workers employed to build sites for the Qatar 2022 World Cup were being mistreated. Vinci has consistently rejected the allegations made against it by Sherpa.
The initial audit which cleared Vinci was carried out in January by various French trade unions and by the Building & Wood Workers International trade union.
Vinci, which counts the wealthy Arab state as its second-biggest shareholder, has several major projects in Qatar linked to the soccer tournament, including a metro line in Doha and a highway.
The French company has denied claims that some migrant workers had seen their passports confiscated and said employees could access their documents stored in safes at any time.
(Reporting by Catherine Mallebay-Vacqueur;Editing by Jean-Michel Belot/Sudip Kar-Gupta/Dominique Vidalon)
