PARIS (Reuters) - French construction firm Vinci on Thursday denied new allegations by human rights group Sherpa that it had violated the rights of migrant workers employed to build sites in Qatar for the 2022 FIFA World Cup.

Sherpa, which previously filed a claim against Vinci that was dismissed by French prosecutors in February, said it had lodged a fresh complaint against the company in France, with new witness statements on alleged abuses.

In a statement, Vinci, which is still pursuing Sherpa for libel over its previous complaint from 2015, said it “refuted, back then and now, all the allegations made by Sherpa”.

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 denied that some migrant workers had seen their passports confiscated and said employees could access their documents stored in safes at any time.

It also said that no serious accidents had been recorded at its construction sites due to high temperatures, and that it had doctors on hand. Sherpa said witnesses had described workers vomiting and suffering from weakness in excessive heat.

“Vinci has always worked towards improving working conditions in Qatar,” the group said.

Qatar has faced several allegations of migrant worker abuse and, under increased scrutiny as it prepares to host the 2022 World Cup, the kingdom has put in place a series of safeguards for workers over the past year.

Sherpa said it was lodging its complaint against Vinci in France together with another non-governmental organisation CCEM (Committee against modern slavery) and six former Vinci workers from India and Nepal.

The allegations are leveled at Vinci’s Construction Grand Projets division as well as its QDVC unit, which is 51 percent owned by Qatari Diar, the property arm of Qatar’s sovereign wealth fund.

Sherpa said it had gathered new testimonies and elements this year in India, where some of the migrant workers originated from.

It accuses the groups and their managers of deliberately endangering people’s lives, forced labor and a failure to provide first aid assistance to workers.

It also alleges employees had to work between 66 and 77 hours a week, on wages that were a fraction of average salaries in Qatar, and were housed in cramped conditions, violating international labor standards.