By KATE BRUMBACK, Associated Press

ATLANTA (AP) — When a respected Iranian scientist left Tehran bound for the U.S. last fall, he had plans to complete the final stage of his research on treating stroke patients as a visiting scholar at the prestigious Mayo Clinic in Minnesota.

Instead, when professor Masoud Soleimani touched down on U.S. soil, federal authorities armed with a secret indictment arrested him on charges that he had violated trade sanctions by trying to have biological material brought to Iran.

Nine months later, as tensions escalate between the two countries, Soleimani sits in a detention center just south of Atlanta embroiled in a legal fight over the application of sweeping U.S. sanctions that have caused prices to skyrocket in Iran.

His lawyers say Soleimani — who works in stem cell research, hematology and regenerative medicine — seized on a former student's plans to travel from the U.S. to Iran in September 2016 as a chance to get recombinant proteins used in his research for a fraction of the price he'd pay at home.

But federal prosecutors say the attempted transport was illegal and secretly obtained an indictment against Soleimani in June 2018. Government officials revoked his visa and arrested him in October when he landed in Chicago.

Soleimani and two of his former students are accused of conspiring and attempting to export biological materials from the U.S. to Iran without authorization. The two counts each carry a maximum penalty of 20 years in prison.

Lawyers for the three scientists say their clients did nothing wrong. They argue no specific license was required because the proteins are medical materials and that bringing them to Iran for noncommercial purposes doesn't amount to exporting goods.

The U.S. attorney's office in Atlanta declined to comment, but prosecutors have argued in court filings that the comprehensive sanctions in place for years do not allow goods to be exported to Iran except under very limited conditions that don't apply in this case.

Soleimani had reached out to Mahboobe Ghaedi, a permanent U.S. resident from Iran who has worked in stem cell research and regenerative medicine at several American universities, about getting some recombinant proteins, the indictment says.

The proteins cost about $8,000 in the U.S. but would have cost Soleimani about $40,000 in Iran, his lawyer Leonard Franco said.

Ghaedi ordered the proteins from U.S. companies and sent them to Maryam Jazayeri, who agreed to bring them to Soleimani when she traveled to Iran to visit family, according to court filings.

Jazayeri, an Iranian-born U.S. citizen who holds a doctorate in clinical biochemistry and lives in Kentucky, was detained and questioned at the Atlanta airport on Sept. 6, 2016, her lawyers wrote in a filing. Customs officials searched her luggage and took the vials of recombinant proteins before letting her board her flight.

When federal prosecutors got an indictment nearly two years later, they filed it under seal, explaining in a court filing that Soleimani lived in Iran but planned to visit the U.S. in the near future and might cancel his plans if the charges were revealed before he traveled.

Franco wrote in a court filing that Soleimani's research "has led to global lifesaving medical advancements in regenerating non-functional human body parts."

The recombinant proteins are used to help speed up stem cell research, Franco said.

"I think that's important because this is not some activity to support terrorism," he said. "This is an activity to heal people, to serve them, not to hurt them."

UCLA bioengineering professor Ali Khademhosseini wrote in a letter submitted with Soleimani's motion to dismiss the charges that the substances have a shelf life of three to six months and "cannot be used for nefarious purposes such as the composition of biological, chemical, or other types of weapons."

An FBI expert who analyzed them reached the same conclusion, defense lawyers noted in court filings.

But prosecutors never mention terrorism. They allege violations of sanctions meant to isolate Iran from trade with the U.S. An exception for medicine and medical devices depends on the way those items are defined under federal law, prosecutors say.

"Notably, items for medical research, including the proteins at issue, are not listed in the definition," they wrote. Those items require a license from the Treasury Department's Office of Foreign Assets Control before they can be exported, prosecutors argued.

As well-educated, intelligent people, the scientists can be reasonably expected to know about the sanctions against their birth country, prosecutors argue. Defense attorneys counter that the sanctions are fluid and vague and the shifting relationship between the countries causes confusion.

The proteins were confiscated from Jazayeri at the tail end of President Barack Obama's administration, which saw a thaw between the two countries.

The U.S. and other world powers announced an agreement with Iran in July 2015 that said that country would curb its nuclear activities in exchange for the lifting of international sanctions, though the U.S. did impose new sanctions after Iran tested ballistic missiles.

After President Donald Trump came into office, tensions escalated and he pulled the U.S. from the nuclear deal in May 2018. Prosecutors in Atlanta got an indictment against Soleimani the following month.

Both Ghaedi and Jazayeri are free on bond. They have both asked to be tried separately, arguing that it appears they were charged as part of a broader investigation that goes beyond the charges against them and that evidence introduced at a joint trial could lead to undue prejudice against them.

A federal magistrate judge in Atlanta declined to release Soleimani, saying he has no legal status in the U.S. since his visa was canceled, so he would have to be turned over to the Department of Homeland Security and could be deported before facing the charges.