"We are still picking up the pieces," he wrote, in a book excerpt published on Sunday by Focus magazine.
Karl-Theodor zu Guttenberg resigned his post as defence minister in early March, after admitting that he plagiarized significant portions of his doctoral thesis. He also dropped his Dr. title, admitting that he made “serious errors,” though unintentionally.
Guttenberg's alma mater, the University of Bayreuth, officially stripped the popular politician of his law doctorate.
Now, his father has come to the disgraced politician's defence, slamming journalists for their relentless coverage of the scandal. He also accused reporters of "publicly bashing" his son and abusing press freedom.
"Relatives and staff were downright ambushed – to the point that people close to me were offered bribe attempts in the five-figures to get information on our private lives," he wrote.
Enoch zu Guttenberg said his son had never given him a reason to doubt his truthfulness. "I can't look into my son's head, but I think I can see into his heart," he said.
Karl-Theodor's task now, Enoch said, was proving the integrity of his character among those who trusted and loved him.
"It's about credibility, which is something you can't lose at high points or in times of defeat," he said. "That's something that he and we have to fight for. Losing credibility would be losing the family's identity."