Justice Minister Brigitte Zypries told the Handelsblatt business daily that she had filed a 25-page legal brief with a court in New York that must give the settlement the green light.
"We hope that the court strikes down the approval of the settlement in the class-action suit, or at least excludes our German authors and publishers from the so-called class so the settlement has no impact on them," Zypries said.
Google reached a class action settlement in October last year with the Authors Guild and the Association of American Publishers to a copyright infringement suit they filed against the Internet powerhouse in 2005.
Under the settlement, Google agreed to pay $125 million to resolve outstanding claims and establish an independent "Book Rights Registry," which will provide revenue from sales and advertising to authors and publishers who agree to digitise their books.
The settlement still needs the approval of a US District Court judge, who is to hold a "fairness hearing" on the deal in New York on October 7.
The deadline for filing complaints is Friday.
Last week, industry giants Amazon, Microsoft and Yahoo! joined an alliance opposing the legal settlement.
Zypries said that ideally German copyright holders should be able to decide for themselves whether Google may make their works available online.
She said the settlement violated international treaties such as the World International Property Organization Copyright Treaty adopted in Geneva in 1996, which stipulates that authors must be asked for permission before their works can be mass distributed elsewhere.
It also threatens initiatives such as the European online library Europeana which she said protected authors' rights.
And it undermines German authors' copyrights although she said Google had pledged to only make the books available online in the United States, Zypries told Handelsblatt.
"We all know that the Internet knows no borders," she said.