The prosecution's star witness in the fraud trial of Minnesota businessman Tom Petters wept as she explained her decision to go to federal investigators.

Deanna Coleman testified that by the middle of 2008, she no longer believed Petters' promises to find them a way out of what prosecutors say was a Ponzi scheme, and pressure from investors was building.

Coleman said when she and her lawyer went to authorities last fall, she had a list showing Petters Co. Inc. owed investors more than $3.5 billion. The investors included some prominent Twin Cities businesspeople, including Ted Deikel, whom they owed $10 million.

Coleman also acknowledged that she and Petters had an intimate relationship in 2005 and 2006. She cried as she recalled Petters promising in those years to get them out of the scheme _ promises she says he never kept.

The 52-year-old Petters, of Wayzata (wy-ZET'-uh), is charged with 20 fraud-related counts. His attorney says he's innocent and that Coleman and others carried out the scheme without Petters' knowledge.