Ashley Alexandra Dupre tells People magazine that the FBI informed her in early March that it was investigating one of her clients. A few days later, she found out which client when she recognized Spitzer on TV -- resigning.
That was March 12, after revelations Spitzer had used Emperors Club VIP, where Dupre worked.
She says she was stricken by the pained expression on Silda Wall Spitzer's face.
"I try not to revisit that place too often, but when I think about his speech, I think of her face, her eyes, the hurt," Dupre said.
Her message to Silda Wall Spitzer: "I'm sorry for your pain."
Dupre, 23, said Spitzer was polite and businesslike when they met. "Some guys, they want to have conversations and really get to know each other. With him, it clearly was not like that," she said. "It was more of a transaction. Strictly business."
Dupre, who was known then as Kristen, said she practiced safe sex with all her clients, including Spitzer. On her attorney's advice, she would not elaborate on their liaison, or say whether Spitzer visited her more than once. She did say that he dressed casually and she did not see his security detail.
Dupre also sat down with Diane Sawyer for an ABC "20/20" segment to be aired Friday. In that interview, ABC said, she describes how an "upper middle-class, girl next door got into the profession and the psychological journey she continues to experience."
Four people have pleaded guilty to running the prostitution operation. Last week, federal prosecutors said they wouldn't bring criminal charges against Spitzer.
Dupre, 23, envisions a future for herself in music, fashion and "writing books" -- but not prostitution. "Never again."