He told the Bild am Sonntag newspaper, “I had to get material for my research into child pornography. As I had none to swap, I had to pay to get some.
“I am innocent and will continue to fight for my seat. My party is waiting for the results of the criminal investigation.”
Claims were made by a child porn dealer in the magazine Focus during the week that Tauss had spent more than €1,000 on illegal images.
The man, named only as Sascha H., admitted sending child porn in the post to a man calling himself Werner who had contacted him with text messages.
Tauss has relinquished all his positions in the SPD parliamentary party, as well as his post as secretary general of the Baden-Württemberg SPD in the light of the investigation.
The party has said it wants to give him the freedom to deal with the allegations.
The Karlsruhe state prosecutor's office said “relevant” child pornography material had been found on Tauss' computer in his Berlin apartment earlier in the month.
Tauss has been in parliament since 1994. He told the media on Thursday that he'd been involved in fighting the child pornography scene for years, adding that he couldn't be sure if the searches were part of a “plot for revenge.”