YANGON, Myanmar (CNN) -- The American man who swam two miles across a lake to visit Aung San Suu Kyi apparently wanted to film the detained Myanmar opposition leader, who refused his request, according to footage played during her trial Thursday.
A television grab shows Aung San Suu Kyi meeting with diplomats at Insein Prison in Yangon on May 20.
Video allegedly shot by John William Yettaw, 53, was played during the trial, which was closed to diplomats and journalists, according to a spokesman for Suu Kyi's party.
Yettaw is a former U.S. military serviceman from Falcon, Missouri.
On the video, the American says that he is at Suu Kyi's house and has asked her to appear in the video, but she refused, according to spokesman Nyan Win, who was inside the courtroom and saw the clip.
It also shows a photo of Suu Kyi's father, with Yettaw telling the camera that it is a photo of Gen. Aung San, Win said.
Suu Kyi, a Nobel Peace Prize laureate, is being tried on allegations of subversion along with two of her maids for the May 3 incident in which Yettaw stayed at her house for at least one night.
If convicted, Suu Kyi could face three to five years in prison.
Yettaw -- who is also on trial -- has been charged with violating immigration laws and trespassing. The charges carry a maximum sentence of five years in prison. He is being represented by a lawyer selected by the U.S. Embassy in Yangon.
Suu Kyi's lawyer has said that his client asked Yettaw to leave immediately, but he refused, first saying he didn't want to swim in daylight for fear of being captured, and later blaming leg cramps. Yettaw finally left May 5 and was arrested shortly afterward.
The trial, which began Monday, is being held inside a prison compound near Yangon, and police maintain a heavy presence outside. It has prompted international criticism with nine Nobel laureates -- including Bishop Desmond Tutu of South Africa -- calling it a "mockery."
U.S. Secretary of State Hillary Clinton called the charges against Suu Kyi "baseless" and accused Myanmar's ruling junta of "continuing (its) resistance to a free and open electoral process." Britain's ambassador was at the trial »
"If they stay on the track they're on, their elections in 2010 will be totally illegitimate and without any meaning in the international community," Clinton said Wednesday.
Myanmar's government has said next year's scheduled elections will reintroduce democracy in Myanmar.
Suu Kyi's trial has been closed to the media and international representatives, except for Wednesday when Myanmar authorities allowed about 20 diplomats and 10 journalists to view the proceedings, which lasted just over an hour.
The government also allowed diplomats from Russia, Singapore and Thailand to meet with Suu Kyi later Wednesday.
A British envoy who attended Wednesday's session said Suu Kyi appeared "robust" and in a positive frame of mind at the brief session.
"She looked extremely alert, extremely in charge of the situation, in good spirits, in good humor at the end," said Mark Canning, Britain's ambassador to Myanmar. "She was very much in charge of her defense team."
Suu Kyi expressed her gratitude to the diplomats who were present in the courtroom. Watch the U.N. secretary general explain what he is doing for Suu Kyi »
"Thank you for coming and your support," she said. "I hope to meet you in better days."
Suu Kyi's lawyers are expected to argue that the pro-democracy advocate knew nothing about the American's plan to visit her and that she tried in vain to get him to leave.
The defense is also expected to turn the charges on their head, arguing that the government failed to protect Suu Kyi.
The court may be trying to issue a verdict before her latest round of home detention expires May 27, according to Win.
Suu Kyi, 63, has been under house arrest for 13 of the past 19 years -- a confinement that the military junta has regularly extended. She has been barred from running for political office, but human rights groups suspect that Myanmar's junta is concerned that her release could invigorate the opposition.
Suu Kyi has been the face of Myanmar's pro-democracy movement and the focus of a global campaign to free her. Her National League for Democracy party won more than 80 percent of the legislative seats in 1990, but she was disqualified from serving because of her house arrest. The military junta ignored the results.
It was during her house arrest that she won the Nobel Peace Prize in 1991. Suu Kyi married a British man, who died in 1999, and they have two sons.
Myanmar's government forbids citizens who bore children with foreigners from running for office.
CNN's Kocha Olarn contributed to this report.