The Duchess of York had been drinking before allegedly offering access to her ex-husband for cash and was "in the gutter", she told Oprah Winfrey.
Her comments come after secretly-filmed News of the World footage appeared to show Sarah Ferguson, 50, offering a reporter access to the Duke of York in return for £500,000.
The interview with the US chat show host is to air on Tuesday.
The duchess flew back to the UK from the US on Saturday.
In footage released to People magazine, the Queen's former daughter-in-law told Winfrey: "I haven't faced the devil in the face because I was in the gutter at that moment.
"So I'm aware of the fact that I've been drinking, you know, that I was not in my right place."
The duchess has also claimed that she is yet to see the full video of her meeting with the reporter.
The former royal has thrived in the US where she has been able to establish a range of business interests before her recent money worries.
The duchess has remained good friends with Prince Andrew despite their divorce.
Their daughters, Princesses Beatrice and Eugenie, are both university students.