A report by a law firm into the 2006 World Cup corruption allegations said Friday it found no conclusive evidence of vote-buying by German bidders. However, the report left open the possibility that it did take place.

"We found no evidence of vote-buying but we also cannot rule it out," said the report by Freshfields, the firm hired by the German soccer federation to investigate the allegations first made by the Der Spiegel magazine on Oct. 16.

The report, presented by Freshfields lawyer Christian Duve at a news conference, said a payment of 6.7 million euros ($7.3 million US) made by the German federation to FIFA on April 27, 2005, was "falsely declared" by the World Cup organizing committee for an opening gala and that the money had been intended for former Adidas chief Robert Louis-Dreyfus.

That same day, FIFA transferred the money to a Swiss account set up by the late Louis-Dreyfus, and former FIFA president Sepp Blatter was aware of the payment, Freshfields said in its report.

Louis-Dreyfus, who died in 2009, had opened the Swiss account in August 2002, shortly before a payment of 10 million Swiss francs — roughly the equivalent of 6.7 million euros — was paid to a Swiss law firm. The Swiss law firm's account also showed previously unknown money transfers with Franz Beckenbauer, who was leading Germany's World Cup bid at the time.

The 10 million Swiss francs was then transferred to a company in Qatar, belonging to disgraced former FIFA official Mohamed Bin Hammam. Its stated purpose was for the TV and marketing for the 2006 Asian Games, Duve said.

Bin Hammam has denied receiving the money, according to the report.

Law firm encountered obstacles

Freshfields said it encountered several "hurdles" in conducting its probe, including missing electronic information, deleted emails, files that weren't accessible and people who declined to talk with its investigators, including Blatter.

"Because of these restrictions, we cannot present a conclusive picture today," Freshfields said.

The firm's lawyers examined 128,000 electronic and other documents and interviewed 31 people.

Duve said some emails had been deleted and that they could not interview some people, including Blatter, whose lawyer declined an invitation.

A contract concluded with now disgraced FIFA official Jack Warner four days before the 2000 vote on the host of the 2006 World Cup also came under scrutiny.

Duve said Warner used some favours mentioned in the deal, such as receiving flags and tickets for his Trinidad and Tobago federation, and had been wined and dined in Germany, but that the economic value of the services was relatively minor.

Reiner Koch, one of the two acting presidents of the German federation, said the contract was "very unusual."

Reinhard Grindel, the federation treasurer who is the only candidate to become its president next month, called for the federation to establish an ethics commission to prevent future affairs.

The report said Wolfgang Niersbach, the former German federation president who resigned in November as the affair began unfolding, did not know about the payment at the centre of the affair until 2015. The report presented no new evidence against Niersbach, who remains on the FIFA executive committee.