A scientist convicted of violating a trade embargo after his family in Iran sent him $3.4 million was sentenced Monday to 2 1/2 years in prison by a judge who noted that the defendant did not support terrorism or funnel money to Iran's government.

Mahmoud Reza Banki, 34, winced when his sentence was announced, and numerous spectators among his more than 50 supporters cried openly or wiped tears.

Banki had faced up to 25 years in prison after he was convicted in June, but even federal prosecutors conceded that the unusual aspects of the case meant that Banki deserved a reduction from the more than five years in prison that sentencing guidelines recommended.

The case drew fresh attention to an informal banking system known as hawalas, which rely on wire transfers, couriers and overnight mail and the dangers they may pose to the U.S.

U.S. District Judge John Keenan described Banki as a "highly educated young man" who was respected by his peers.

In a nod to a letter written on Banki's behalf from 2003 Nobel Peace Prize recipient Shirin Ebadi, the judge said he was "certainly impressed that a Nobel Peace Prize recipient took the time to write."

The judge minimized any suggestions of a threat to national security, saying Banki "did not support terrorism or the Iranian government."

Banki's attorney Baruch Weiss asked the judge to let his client go free, saying the seven months he has spent in prison since his arrest were sufficient. Weiss said Banki wanted to return to his dream of finding ways to finance stem cell research so replacement organs such as kidneys could be produced without the need for donors.

Banki told the judge that his isolation in prison had allowed him plenty of time to think.

"I've agonized over and over what could I have done differently," he said.

Calling himself "battered but still motivated," he said he was "older, wiser and more distraught than ever before."

Banki, born in Tehran, obtained undergraduate degrees from Purdue University and the University of California at Berkeley before getting a doctorate in chemical engineering from Princeton University. He has been a U.S. citizen since 1996.

A jury convicted him of violating the Iran trade embargo and operating an unlicensed money transmitting business. He also was convicted of charges that he made false statements.

The trade embargo, initiated in 1995, prohibits U.S. citizens from supplying goods, services or technology to Iran or its government.

Banki's lawyers argued at trial that Banki had $3.4 million deposited into his bank accounts by family members and was unaware that a hawala allowed for an equal amount of money move into Iran.

In a presentence letter to the court, the government highlighted the threat to national security that it believes hawalas pose, saying "financial transactions with a country supporting international terrorism implicate national security by definition."

It said funds transferred to Iran are inevitably used to strengthen Iran's economy.

"This — the strengthening of the economy of a country that supports international terrorism — is exactly what the embargo was designed to avoid," the government wrote.

The U.S. government also accused Banki of using the money sent to him by his father to invest in a home and securities and "to finance a lavish lifestyle."

The judge has signed an order requiring Banki to forfeit the $3.4 million. Weiss said Banki will appeal his conviction and the forfeiture order.