John Yettaw, 53, who is also on trial at Insein Prison in Yangon, said he dreamt that Suu Kyi, a Nobel Peace Prize winner who was under house arrest, had been killed by terrorists, The Daily Telegraph reported. He interpreted that as a vision from God.
Nyan Win, Suu Kyi's lawyer, summarized the testimony after the closed door proceedings.
Yettaw testified police officers saw him swimming across the lake on May 5 and threw stones at him, CNN said.
Suu Kyi, whose current house arrest order expired Tuesday, faces five years in prison if she is convicted of violating its terms. Yettaw faces charges that include "illegal swimming" as well as violations of security and immigration laws, the Telegraph said.
In a statement, Suu Kyi blamed the officers guarding her house for failing to keep Yettaw out.
Critics suggest that the military junta ruling the country formerly known as Burma want Suu Kyi behind bars during elections next year.