Quethlie Alexie, who worked as a nanny for the celebrity model in the Bahamas, acknowledged under tough cross-examination that she had signed a sworn affidavit saying she saw Stern inject Smith with a white substance.
She then retracted that claim and a number of other statements.
Stern's attorney, Steve Sadow, asked, "You did not see anyone inject anything into Anna Nicole?"
"No, I did not," Alexie testified.
"And that is the truth?" Sadow asked.
"Yes, I never said I saw anyone," the witness said, speaking through a Creole interpreter.
Sadow then read from the affidavit filed as part of a 2007 lawsuit by Smith's mother in which Smith is referred to as Mrs. Marshall, her legal name.
"Didn't you say, 'I personally observed a white substance being heated in a spoon by Mrs. Marshall in her bathroom. I then observed Mr. Stern tie a band on her arm and inject the substance into her arm,"' Sadow said.
At first, Alexie said she couldn't understand the question, but when Sadow repeated it, she said, "One time I saw something tied on her arm but not the syringe."
Sadow tried to ask if she had changed her story because the autopsy on Smith showed no needle tracks on her arms. But the prosecution objected, and the judge barred the question.
Alexie has testified that she saw Stern, who was Smith's lawyer-boyfriend, and Dr. Khristine Eroshevich, another defendant, take Smith into a bathroom. When they left, she found a bloody syringe, cotton and burned spoon of liquid, Alexie said.
Eroshevich's lawyer Brad Brunon asked Alexie why the witness did not mention the items in her first affidavit provided to an attorney in the Bahamas.
"I did speak about it, but they didn't put it in," the witness said.
He asked if she began making those statements when she learned she could sell her story for a lot of money. She denied doing that.
Alexie also testified that Smith was virtually unconscious from drugs for most of the three months she worked for her.
There was confusion, however, about Alexie's claim that Smith slept for two days at a time after drinking from a bottle of medicine.
"When I say sleep, it's wake up, talk, laugh, go to sleep again," Alexie said
Stern, Eroshevich and Dr. Sandeep Kapoor have pleaded not guilty to multiple charges, including providing Smith with excessive opiates and sedatives. They are not charged in her overdose death in 2007.
Brunon also quizzed Alexie about an explosive claim that Bahamas immigration minister Shane Gibson had a sexual relationship with Smith and gave her preferential treatment in obtaining resident status.
The claim, along with a picture of him in bed with Smith while fully clothed, led to his resignation. Asked if she had said Gibson visited Smith in her bedroom frequently, Alexie said, "No, I didn't say that ... He never went in Anna's bedroom."
Sadow also quizzed Alexie about a baby shower that was held for Smith at the Bahamas home during the period Alexie said Smith was semiconscious. Alexie claimed Smith was asleep and had to be carried in to the event.
Sadow then produced 20 photographs of the balloon-festooned shower and displayed them on a big screen for jurors. The images showed Smith dressed up and smiling, holding up the baby for the camera, cutting a cake and displaying gifts.
Sadow asked Alexie to explain the pictures.
"Everything she got they put in her hands to hold up," she said.