He added: "We have the law on our side, but we don't know if the judges are on our side."
Reports said security around the Insein jail on the outskirts of the fomer Myanmar capital was tight with roads blocked and police manning barbed-wire barricades.
"We have the law on our side, but we don't know if the judges are on our side"
Kyi Win, lawyer for
Aung San Suu Kyi
The opposition leader is accused of violating the terms of her detention by allowing an uninvited American man, who secretly swam to her lakeside home, to stay for two days.
The American, John Yettaw, is also on trial along with two female aides to Aung San Suu Kyi.
The opposition leader's legal team has not contested the basic facts of the case, but they have argued that the charges she faces are illegal because the military government charged her under a law that cites a constitution abolished two decades ago.
They have also asserted that the guards who monitor her home and ensure that she remains inside her compound should also be held responsible for any intrusion on her property.
The court is expected to deliver its verdict sometime next month.
The trial lasting several weeks has been mostly held behind closed doors inside Yangon's Insein jail.
However, for Fridays closing arguments diplomats from the UK, France, Germany, Norway and Italy were expected to be allowed into the court, the Associated Press reported.
The court has heard from 14 prosecution witnesses but only allowed two defence witnesses to appear.
Call for release
On Thursday the US secretary of state, Hillary Clinton, reiterated calls for Myanmar's military government to free Aung San Suu Kyi and more than 2,000 other political prisoners held in the country.
Clinton also urged members of the Association of Southeast Asian Nations (Asean) to consider expelling Myanmar unless it ends her detention, but Thailand, which currently chairs the regional bloc, rejected the call.
Aung San Suu Kyi has been held in jail or under house arrest for 14 of the past 19 years.
Rights groups and opposition supporters have condemned the charges against her as a sham trumped up by the military to keep her in jail during national elections it has said will be held next year.