Updated

Imprisoned Ponzi king Bernard Madoff's longtime secretary plans to defend herself from the witness stand at her trial on charges she aided the historic fraud, her lawyer says.

Attorney Roland Riopelle told the trial judge in a letter Saturday that Annette Bongiorno expects to testify, though he noted that she could change her mind at the last minute. He notified the judge because Bongiorno's defense presentation is expected to begin Monday.

It will follow several days of testimony by another defendant, Daniel Bonventre, Madoff's former director of operations. Bonventre, Bongiorno and three other Madoff ex-employees are accused of assisting Madoff in a fraud that cheated thousands of investors out of nearly $20 billion.

The fraud was revealed in December 2008 when Madoff ran out of money and confessed that he had been running a Ponzi scheme for decades.

The defendants say they were all duped by Madoff, just the same as federal regulators and sophisticated investors who say they had no idea he was operating a massive fraud.

In his letter to the judge presiding over a trial that has lasted several months, Riopelle said he wanted to notify the court and other lawyers in the case that "Mrs. Bongiorno wishes to exercise her right to testify in her own defense."

However, he added that his client "will reserve the right to change her mind any time before the end of her case, and I intend to call her as the last witness in her case. But her intention at present is to testify."

Prosecutors have said fictitious trades and phantom accounts were created with help from Bongiorno, who was a supervisor in Madoff's private investment business.

During his testimony, Bonventre said he was unaware of Madoff's crimes as they were happening. He said he ran the legitimate side of Madoff's business.