The political party of detained Burmese democracy leader Aung San Suu Kyi says she is facing trial Thursday and could be sentenced for up to five years in prison.  Her party says the trial is an excuse to keep her locked up.

Burmese authorities are expected to take Aung San Suu Kyi to court Thursday morning, along with two of her assistants.

The sudden trial is believed to be related to bizarre reports last week of an American man sneaking into her compound.  

The man was arrested after swimming across a lake and spending two nights in Aung San Suu Kyi's residence.

In military-run Burma, it is illegal for foreigners to stay overnight in the homes of locals.

Nyan Win is a spokesman for her political party, the National League for Democracy.  He says the party asked Burmese authorities why she would be put on trial but they refused to answer.

"I think this is not a criminal issue.  This is a political issue?Their motivation is to extend her detention.  Her present detention expires on 27th May," he said.

Nyan Win says he thinks the three will be charged with violating state security and could be sentenced from three to five years in prison.

The U.S. State Department has confirmed the American man was arrested, but say Burmese authorities have not charged him with any crime.

Nyan Win says the trial of Aung San Suu Kyi will be held at a court attached to Insein prison -- a notorious detention center that holds many Burmese dissidents and where rights groups say abuse of prisoners is common.

He worries about her health, if she is imprisoned. "According to her doctor, Daw Aung San Suu Kyi has improved.  But, if she was sentenced so?five years, three years, she will be in?health will be very dangers," he said.

The Nobel Peace Prize winner's health has been a concern after she was treated for dehydration over the weekend.  

Aung San Suu Kyi's NLD party won the country's last elections in 1990 but Burma's military rulers ignored the results and have held her under house arrest for most of the last 18 years.

The Burmese generals have set a new election for 2010, as part of a plan they call a "road map to democracy."  However, in the last year the Burmese military has arrested hundreds of political prisoners.  More than 2,000 are now imprisoned.