TORONTO — A Toronto man found guilty of trying to send devices to Iran that could be used to build nuclear weapons has been sentenced to another 20 months behind bars.

Earlier this month a judge convicted Mahmoud Yadegari of nine of the 10 charges he was facing -- he was acquitted of one count of forgery.

On Thursday he was handed a four-year, three-month sentence, but with double credit for time served it amounts to an additional 20 months in jail.

Yadegari, 36, was arrested in April 2009 after a joint eight-week investigation by the RCMP and the U.S. Department of Homeland Security.

He is believed to be the only Canadian ever charged under the United Nations Act.

Yadegari was also charged under the Criminal Code, the Customs Act and the Export and Import Permits Act, as well as provisions in Canada's Nuclear Safety and Control Act.

Some of the offences Yadegari was found guilty of carry maximum sentences of 10 years in prison and $500,000 fines.

The Crown was seeking a 6 1/2-year sentence.

The case has received international attention and even the notice of Iranian President Mahmoud Ahmadinejad.

In February, Ahmadinejad proposed that Yadegari be included in a swap of Iranians in U.S. prisons for three American hikers being held in Tehran.

Yadegari, an Iranian-born businessman, used a small company operated out of his Toronto home to try to export to Iran via Dubai two of 10 pressure transducers he purchased from a U.S. company.

The hand-sized instruments convert pressure measurements into electrical signals for computers and other electronic devices. They have benign applications but can be used in the enrichment of uranium for nuclear weapons.

Iran insists it is enriching uranium to produce nuclear energy for civilian purposes. But the United States and some European countries accuse Tehran of secretly seeking to build nuclear weapons.

At a news conference following his arrest, police said Yadegari purchased the transducers from a Boston-area company for about $1,100 each. Police said the company alerted authorities.

Yadegari is a Canadian citizen who emigrated from Iran in 1998.