The government said that personal data and documents from hundreds of German politicians and public figures, including Merkel had been published online.
The Social Democrats only have the support of 17% of the German electorate.
The Czech Republic has been in the midst of a political deadlock for half a year, but this may soon end.
Forming a government with the Communists and SPD party would give Prime Minister Andrej Babiš's ANO party a parliamentary majority.
Despite Berlin's firm position with Moscow, channels of communication will remain open.
Ralph Brinkhaus said conservatives would insist on averting new government debt and planned to examine any European spending plans very carefully.
All three parties in German Chancellor Angela Merkel's coalition have recently been losing ground to the far-right Alternative for Germany.
Chancellor Angela Merkel's best hope of securing a fourth term lies with the SPD.
Thomas Oppermann, vice president of the Bundestag lower house of parliament, told Die Welt newspaper that he expected a "clear approval" rate of 55% in an SPD postal ballot that ended on Friday, with results to be unveiled on Sunday.
Schaeuble stepped down as finance minister after the election to become president of the Bundestag.
After German Chancellor Angela Merkel's CDU made many concessions to the SPD, the Young Union has demanded that the CDU find a successor to Merkel.
The CDU and SPD's proposed coalition may be splintered by disagreements over healthcare and labour issues.
Andrej Babiš will continue talks with the CSSD, Communists, and SPD to attempt to form the new government of the Czech Republic.
After the Social Democrats voted to pursue coalition talks, German Chancellor Angela Merkel is now a step closer to forming her desired coalition.
A coalition between the SPD and CDU has been jeopardized by disagreements over a myriad of issues.
German Chancellor Angela Merkel's party, the Christian Democratic Union, has agreed to attempt to broker a coalition with the Social Democratic Party.