Nobel Peace Prize laureate Aung San Suu Kyi is charged with violating a restriction order that bars her from contact with the outside world. (Associated Press)

Riot police stood guard outside Burma's main prison Friday as a court inside heard from the last defence witness in the trial of pro-democracy leader Aung San Suu Kyi.

Khin Moe Moe, a lawyer and a member of the National League for Democracy party, argued during more than three hours of cross-examination that Suu Kyi violated no existing laws because she was charged under a constitution that was abolished in 1988.

He later told reporters outside the Insein Prison in Rangoon, where about 100 Suu Kyi supporters had gathered, that Suu Kyi looked "healthy and alert."

The nearly seven-hour session ended with the court setting July 24 for final arguments in the case, though a verdict is not expected on that date. If convicted, Suu Kyi faces up to five more years in prison.

She was charged May 14 after American John William Yettaw, 53, swam across a lake and allegedly snuck into her home for two days.

According to Suu Kyi's restriction order, she is prohibited from having contact with embassies and political parties and she is barred from communicating with the outside world.

The 64-year-old has already spent more than 13 of the last 19 years, including the past six, in detention and house arrest without trial for her non-violent promotion of democracy in Burma, also known as Myanmar.

Human rights groups and the international community have derided the trial as a pretext to keep Suu Kyi imprisoned before 2010's national elections.

With files from The Associated Press