The new military regime has already issues several criminal charges against the Nobel laureate since she was detained alongside top political allides last month, including owning unlicensed walkie-talkies and violating coronavirus restrictions.
On Wednesday night, military broadcaster Myawady aired a video of a Myanmar businessman confessing to giving her a total of $550,000 over several years.
Maung Weik said he had donated money to senior government figures for the good of his business.
“Aung San Suu Kyi committed corruption and (authorities) are preparing to charge her according to anti-corruption law,” an announcer said during the broadcast.
This is not the first time corruption allegations have been lodged against her.
Last week a junta spokesman said a now-detained chief minister had admitted to giving her $600,000 and more than 10 kilograms (22 pounds) of gold bars.
“Those accusations are groundless and illogical,” Suu Kyi’s lawyer Khin Maung Zaw told AFP.
“Aung San Suu Kyi may have her defects… but bribery and corruption are not her traits,” he said, adding that most people in Myanmar will not believe the allegations.
Myanmar has been in uproar since February’s coup, with hundreds of thousands of protesters flooding streets demanding a return to democracy and the release of Suu Kyi.
The junta has justified the move by claiming electoral fraud in elections last November that were won by Suu Kyi’s party in a landslide.
Security forces have increasingly stepped up lethal force against demonstrators.
Local monitoring group the Assistance Association for Political Prisoners has reported the killing of more than 210 people in crackdowns across the country.