Kyaw Zaw Lwin was charged Friday during his trial inside Myanmar's notorious Insein Prison with violating the Foreign Exchange Regulation Act, which carries a three-year prison sentence, lawyer Nyan Win said.

Lawyers were not told why the new charge was added or given details of how their client allegedly violated the act, which bars Myanmar nationals from holding foreign currency without a license. It also limits the amount of money that can be brought in and out of the country.

"It is not clear yet why he was charged under the Foreign Exchange Regulation Act," Nyan Win said.

Kyaw Zaw Lwin was arrested on arrival at Yangon airport on Sept. 3. He was accused of plotting to incite unrest in the military-ruled country but was then charged Oct. 14 with forgery for allegedly making a national identity card. He was also charged with fraud. Each charge carries a prison term of seven years.

The trial is scheduled to resume Friday, Nyan Win said.

Myanmar authorities accused Kyaw Zaw Lwin of entering Myanmar to stir up protests by Buddhist monks, who led pro-democracy demonstrations in 2007 that were brutally suppressed by the junta. Authorities said he confessed to plotting with dissident groups outside the country, and accused him of links to several activists inside Myanmar who planned to set off bombs.

Kyaw Zaw Lwin denied allegations that he was plotting to incite unrest.

His mother is serving a five-year prison term for political activities and his sister was sentenced to 65 years in prison for her role in the 2007 pro-democracy protests, activist groups and family members said.