The University of Pennsylvania Law School didn't do an Iranian professor, considered one of the leading thinkers on human rights in the Middle East, any favors when it invited him to teach here.

Mehdi Zakerian, assistant professor of human rights at an independent university in Tehran, was arrested by Iranian officials, reportedly in mid-August.

He was released on bail several weeks ago, according to a statement from Penn yesterday.

But the Iranian government has not returned Zakerian's passport to him, and he has been charged with espionage and is to be put on trial, according to the statement.

Amnesty International said that Zakerian's detention "may be a politically motivated attempt to stop him from from traveling to the U.S.A." to take the job as a visiting scholar.

"Our invitation to him remains open and we are hopeful that we will be able to welcome Professor Zakerian to Philadelphia in the near future," Michael A. Fitts, dean of Penn law school, said in the statement.

William Burke-White, a professor at the law school and an expert in international law, said that Zakerian was "one of the leading thinkers on human rights in the Middle East."

Burke-White said that Zakerian's writings "have helped us all better understand the relationship between human rights and Islam."

If permitted, Zakerian could begin teaching here in the spring, he said. Whether that will occur is debatable.

"Following the election of President Mahmoud Ahmadinejad in 2005, Iranian intelligence authorties have increased presssures on journalists, academics, human-rights defenders and others perceived as having links with foreign countries or having been involved in initiatives to build Iran's civil society," according to Amnesty International.

Iran is a theocracy, where clerics have the final say.

Amnesty International quoted an Iranian online publication as saying that Zakerian had been held in a "Ministry of Intelligence detention center."

Zakerian was able to meet with his family in a courtroom early in September but wasn't released until several weeks ago, Penn's statment said.

Amnesty International quoted Zakerian's family as saying that he looked "weak." *