A six-month misconduct investigation of U. California-Berkeley professor Peter Duesberg has ended with the receipt of a letter from campus officials clearing him of wrongdoing.

The letter, dated May 28, said a 2009 article co-authored by Duesberg – which was withdrawn from the scientific journal Medical Hypotheses after its publication – did not violate campus policy, adding that his right to publish the article was protected “under the umbrella of academic freedom.”

The investigation began when campus and UC officials received two letters of complaint – one from activist Nathan Geffen of the Treatment Action Coalition in South Africa and one from an anonymous author – against Duesberg’s article.

The article was a response to a 2008 study by professors from Harvard University who disputed Duesberg’s challenge of the link between HIV and AIDS and claimed his research was in part responsible for delays in the distribution of anti-HIV drugs and the loss of 330,000 South African lives.

Duesberg’s article was permanently removed by the journal’s publisher in 2009, despite opposition from its editor, Bruce Charlton, who was later fired when he refused to implement a peer review procedure at the journal.

The campus investigation – conducted by Arthur Reingold, a professor at the campus school of public health – addressed concerns about “issues of credibility and false claims” within the article as well as whether Duesberg failed to disclose an alleged conflict of interest.

Reingold could not be reached for comment Tuesday.

In the May 28 letter to Duesberg, Sheldon Zedeck, vice provost for academic affairs and faculty welfare, said the end of the investigation did not express any position on the part of the university as to the accuracy or validity of his article.

“The university’s investigation did not undertake to evaluate the merits of your research, but concluded that your right to publish and disseminate your views is protected under the umbrella of academic freedom,” he said in the letter. Zedeck could not be reached for further comment Tuesday.

Geffen said he filed a complaint against Duesberg because he was concerned about the relationship between David Rasnick, a former visiting scholar at UC Berkeley and co-author of the article, and a company that distributes alternative treatments for HIV. He said it was an ethical breach that should be addressed.

But Duesberg said the claims were unsubstantiated and that the withdrawal of his article was a violation of his right to free speech.

“It comes close to some sort of theft,” he said. “To take (the article) away without giving a reason is like taking away your car or house. What you work for is all denied, taken away without explanation.”

Rasnick said the investigation was never justified.

“It was ridiculous from the beginning – Duesberg hasn’t said anything different in his paper over 20 years,” he said. “Nobody ever pointed out a mistake that suggested scientific misconduct.”

Daniel Melia, secretary for the campus division of the Academic Senate, said Duesberg was within his rights in publishing the article, but that it is not unusual for people to make complaints against controversial studies.

“The university has an obligation to protect unpopular and dissenting views,” he said. “People should be able to express unpopular views because freedom of inquiry allows them to do so through any type of search which is protected by the university.”

Duesberg said he will continue his research and that he hopes he will have the opportunity to publish his article in another journal.

“Having someone tell you your paper is going to be censored without giving a name and without giving a reason is a devastating experience,” he said. “The fact that the investigation was dropped restores a good part of my confidence in our university.”