Jacob Zuma's 20-year-old daughter, Duduzile, will defend her father in court against claims that he raped a family friend.

It emerged yesterday that Duduzile Zuma would tell the Johannesburg High Court that she believed the complainant was "dressed inappropriately" when visiting Zuma in his study on the night of the alleged rape, clad only in a kanga (wrap).

Zuma is accused of raping a 31-year-old family friend and HIV activist, who testified yesterday she had been a victim of rape before Zuma allegedly sexually assaulted her, after she had spent the evening with him and several other people in his Forest Town home on November 2.

Duduzile Zuma's evidence could prove crucial to Zuma's claims that his sex with his alleged rape victim was consensual.

During his cross-examination, Zuma's counsel, Kemp J Kemp SC, said Duduzile Zuma would testify that:

She had offered the complainant a lift home on the night of the alleged rape, at the same time as she took another of her father's guests home, but the complainant had refused the offer.

After visiting Duduzile's room later that night and asking her for a book to read so that she could fall asleep, the woman had said she "wanted to talk" to Zuma.

On the way to her father's study, Duduzile had given the complainant a book.

Duduzile had then left her alone with Zuma in his study.

Referring to the complainant's clothing at the time, Kemp said: "It struck Duduzile as quite inappropriate for you to go and speak to her family in that state."

While admitting that she had been wearing a kanga, the complainant said she could not remember telling Duduzile that she needed to speak to Zuma.

"I don't remember having anything that I needed to say to umalume (uncle)."

She said she had spent four hours with Duduzile on the night of the alleged rape attack.

Kemp's detailing of Duduzile's claims was not the last time she was mentioned in court yesterday.

During his cross-examination of the complainant about a conversation with Intelligence Minister Ronnie Kasrils the day before she laid a rape charge against Zuma, Duduzile was again brought into play.

Pointing out that Kasrils's statement about his conversation with the complainant had described her as a "close friend" of Zuma's daughter, who had been staying in his house, Kemp asked the complainant where Kasrils would have got that from.

She replied: "I wouldn't really know, except to say that I know other children of (Zuma's)."

She said she had contacted Kasrils, who she had been in "constant contact" with regarding study sponsorship since 2004, to inform him that she had been raped by Zuma and to seek his advice about the witness protection programme.

Kasrils, who is on the State's list of witnesses, claimed in his statement that he had informed the complainant that he was not in any position to give her advice because of the politically sensitive nature of her claims. He had told her that she "should do what she considered right".

The complainant told Kemp yesterday that Kasrils had said he was "sorry" about what had happened to her.

Kemp also suggested that she harboured negative feelings towards Zuma because of his failure to sponsor her planned studies in the UK, a suggestion she vehemently denied.

"I was not disappointed in him. I knew that he had tried his best and I witnessed his attempts to help me," she said.

Throughout the day, Zuma, in a dark suit, intently followed the cross-examination of the complainant, during which she grew quickly fatigued and at times admitted that she "was lost".

With acknowledgement to Jeremy Gordin, Karyn Maughan, Gill Gifford and Cape Argus.