Presiding judge Frank Rosenow of the regional court in Hanover said on Thursday that he had found no proof of criminal wrongdoing. The court also awarded the ex-president damages for "losses suffered" during police raid on his home.

Wulff had been accused of accepting favors while in public office, during his term as state premier of Lower Saxony before he became president.

The charge was that he had accepted an invitation worth 754 euros ($1,030) by businessman and film financier David Groenewold to Munich's Oktoberfest in 2008.

Two months after that trip, Wulff wrote a letter to the CEO of the Siemens company on behalf of Groenewold, seeking the firm's support for the Groenewold's new film.

The prosecution linked these two events, but failed to prove their case. The claim was the only remaining charge prosecutors leveled against the former president, after initially investigating whether he took favors from other wealthy friends

More than 20 witnesses were heard in the high-profile trial, which started in 2013 with Wulff vowing to restore his name and honor.

Reputation tarnished

The 54-year-old, a former conservative party rising star, insisted he was innocent of corruption or accepting favors and declined to settle the case with a fine. Had he been convicted on the corruption charges, he could have faced up to three years in jail.

Wulff became the youngest German president in 2010, but quit office after only 20 months.

Germans look to their president as a role model and source of moral authority, but Wulff's reputation suffered when it emerged that he had threatened the editor of the tabloid newspaper Bild with "war" should the outlet publish details on a cheap home loan he had received from a businessman friend. A stream of allegations followed ranging from free flight upgrades to stays in luxury hotels and precious gifts.

Wulff's resignation marked the end of his political career and dealt a blow to Chancellor Angela Merkel, who had hand-picked him for office. He remained in the headlines, also because his young wife Bettina then divorced him and published a book on her life as a first lady.

Wulff's friends and supporters claimed that trifling charges had been trumped up in a conspiracy to tarnish his name; Wulff's critics claim the trial was necessary to take him to court to prove that no German public official stands above the law.

The ex-president's story has been the subject of news shows, talk shows, and front page articles in Germany. The verdict coincides with the release of a feature film on his life.

rg/dr (AFP, dpa, Reuters)