German prosecutors say they are "monitoring" claims of bribery relating to the country's successful bid to host the 2006 World Cup.
Der Spiegel alleges the bid committee of the German Football Association (DFB) bought votes using a £4.9m fund.
The DFB denies the allegations.
A spokeswoman for the Frankfurt state prosecutor's office said it had not opened a formal investigation but had "initiated a monitoring process" that would find out if one was required.
German news weekly Der Spiegel says the fund was set up using money loaned by the late former Adidas boss Robert Louis-Dreyfus.
It alleges the funds were later repaid to Dreyfus in 2005 - using Fifa as cover - when the German World Cup organising committee made a contribution of 6.7m euros for a gala opening ceremony at Berlin's Olympic Stadium, which was later cancelled.
Der Spiegel also claims 2006 World Cup organising committee president Franz Beckenbauer and current DFB president Wolfgang Niersbach were aware of the fund. Both men have denied the allegations.
Speaking on Monday, Niersbach said: "We entered the competition with legal means and we won it with legal means. There were no slush funds, there was no vote purchase.
"This money transfer from our organising committee to Fifa is being investigated internally by the control committee in charge."
Former West Germany captain Beckenbauer said he "never gave money to anyone to acquire votes", and was "certain that no other member of the bidding committee did either".
In a statement released on Friday, the DFB said it "categorically rejects" the newspaper's "baseless allegations" and would be taking legal action.
Fifa said it would investigate the "serious allegations".
Germany narrowly won the vote, held in 2000, by 12 votes to 11, with South Africa second.
World governing body Fifa was engulfed by the biggest corruption scandal in its history in March.
Following a major inquiry by the Federal Bureau of Investigation, 14 football officials and sports marketing executives were indicted in the United States on charges of "rampant, systemic, and deep-rooted" corruption.
Meanwhile, a separate Swiss investigation is looking into the bidding process for the 2018 and 2022 World Cups, which will be held in Russia and Qatar respectively.
Suspended outgoing president Sepp Blatter, 79, is also under investigation by Swiss prosecutors over allegations he signed a contract that was "unfavourable to Fifa" and made a "disloyal payment" to European football chief Michel Platini, who has also been suspended by Fifa.