FRANKFURT - 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 361-page report, which sought to explain a complicated chain of financial transactions at the centre of the case, indicated that the involvement of former Germany great Franz Beckenbauer went beyond what was previously believed.

The report, presented by Freshfields lawyer Christian Duve at a news conference, said a payment of 6.7 million euros ($7.3 million) 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 Beckenbauer, who was leading Germany's World Cup bid at the time, and his manager Robert Schwan, who has also died since.

The total sum paid by them into the Swiss account was 10 million Swiss francs ($10 million), shortly before the transfer from Louis-Dreyfus,

The 10 million Swiss francs was then transferred to a company in Qatar, belonging to now-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. The Qatari had been a member of FIFA's executive committee and FIFA's financial commission.

The report failed to explain the final purpose of the money.

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 and FIFA treasurer Markus Kattner.

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

FIFA said Friday that Swiss authorities had asked its officials and Kattner not to respond to "any enquires of third parties."

"FIFA continues to co-operate with the investigating authorities. In fact Mr. Kattner and FIFA were requested to prioritize their response to the Swiss investigating authorities," a statement said.

Swiss federal prosecutors investigating FIFA said their work could be harmed by the Freshfields report because it risks helping suspects or witnesses collude.

The payment investigated by Freshfields is also part of a wide-ranging Swiss probe of FIFA. Criminal proceedings have already been opened against Blatter for separate allegations of financial misconduct.

"Publication of respective reports does increase the risk of collusion," Switzerland's attorney general's office said.

In a statement to The Associated Press, the Swiss federal office said it "deeply regrets" publication of the German report.

Freshfields lawyers examined 128,000 electronic and other documents and interviewed 31 people.

A contract concluded between Beckenbauer and the now-disgraced FIFA official Jack Warner four days before the 2000 vote on the host of the 2006 World Cup also came under scrutiny. After successfully leading the bid, Beckenbauer later headed the organizing committee.

Although the contract never formally went into force, 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 the 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 scandals.

The report said Wolfgang Niersbach, the former German federation president who resigned in November as the affair began unfolding, became aware of the payment in June last year and not only in October, as he previously claimed. Niersbach remains on the FIFA executive committee.

Frankfurt prosecutors are conducting a tax evasion investigation of Niersbach, his predecessor Theo Zwanziger and another former DFB official.

Duve said his firm was unable to see documents in possession of Frankfurt prosecutors, who raided the offices and residences of DFB officials.