Supermodel Naomi Campbell named Charles Taylor as the person who gave her a "huge diamond", actress Mia Farrow told the former Liberian leader's war crimes trial today.
Farrow contradicted Campbell's account that she was given two or three "dirty looking pebbles" but did not know what they were or who they were from.
She told the Special Court for Sierra Leone in The Hague, the Netherlands, that when Campbell came down to breakfast after a party hosted by Nelson Mandela in South Africa in 1997, the model told the other guests an "unforgettable" story.
Farrow said: "Before she even sat down she recounted an event of that evening.
"And she said that in the night she had been awakened, some men were knocking at the door. They had been sent by Charles Taylor and they were giving a huge diamond.
"And she said that she intended to give the diamond to Nelson Mandela's children's charity."
Giving evidence last week, Campbell said she was woken in the night by two men knocking at her door who gave her a pouch of "dirty looking pebbles".
Campbell, 40, said there was no explanation about who the gift was from.
She said either Farrow or her former agent, Carole White, made the suggestion at breakfast the stones were diamonds and that they were from Taylor.
But asked about where the suggestion came from, Farrow said: "Miss Campbell. Miss Campbell entered the room. She was quite excited and said in effect, 'Oh my God, in the middle of the night I was awoken by knocking at the door and it was men sent by Charles Taylor and he sent me a huge diamond."'
Farrow was asked repeatedly by prosecutor Nicholas Koumjian about her recollection of who said the diamonds were from Taylor.
She insisted: "Naomi Campbell said they came from Charles Taylor."
Taylor, the former president of Liberia, is accused of war crimes during Sierra Leone's civil war, including using diamonds to fund rebels.
He denies 11 charges, including murder, rape, sexual slavery and recruiting child soldiers.
Farrow said when she arrived at the party, Taylor was already there.
Nelson Mandela's partner, Graca Machel, told her: "'No, no, you don't want to be photographed with this man. This is the president of Liberia. He's not supposed to be here,' or 'he should have left by now'.
"She moved the children and me to another area."
She told the prosecution she did not know anything about Taylor before the dinner other than Ms Machel's reaction.
She said: "I gathered he was someone of disputable character.
"But I really didn't know in 1997 anything about him."
Asked if she knew at the time of the war in Sierra Leone, she said she had "only the vaguest" idea.
And she said she knew of no connection between Taylor and diamonds.
Under cross-examination from defence lawyer Morris Anyah, Farrow said: "I also discussed it with my children and they remember exactly the same thing."
Farrow's three children, Matthew Previn, Malone Farrow and Ronan Farrow, were also at the dinner in 1997, at the time aged about 17, 12 and 10.
The actress said she was "fuzzy" about other details around the breakfast but not the supermodel's story.
She said: "It was an unforgettable moment."
Farrow said she did not see the diamond or diamonds and could only give evidence about what she recalled Campbell saying.
She said: "To the best of my ability she said 'a large diamond'. That's what she said."
Farrow added she could not remember certain details, such as whether Taylor stayed for dinner and how many men were said to have knocked on Campbell's door.
She said: "Even when the prosecution contacted me I didn't remember what year it was."
The court was shown a photograph taken at the party in which Taylor is standing between Mr Mandela and Campbell.
Farrow was asked why such a photograph was taken when, according to her, Ms Machel told her Taylor was not welcome.
The actress said: "I can only tell you what she said to me and what I deduced from that is that he was not invited to dinner and she was trying to get him to leave.
"That said, he was the president of Liberia and I assume she had certain formal obligations."
Farrow was asked again if it was possible she was mistaken about who said the gift was a diamond or diamonds and that it was from Taylor.
She said: "It is not possible."
Taylor's defence asked: "Is it possible that someone else there present made those remarks?"
She replied: "It was Naomi Campbell who said them."
Under repeated questioning she said: "I didn't mishear.
"I don't know how many diamonds there were or what state they were in because I didn't see them.
"I can only tell you, and I swear on the Bible to this court and beyond, that is what Naomi Campbell said that morning at breakfast."
Farrow said that, until she was contacted by the prosecution, she did not realise the information she held was important.
She said: "I didn't realise it was consequential.
"Yes, I regret that I didn't put it together earlier, I suppose. Anyway, that's when I remembered it."
Farrow told the court: "If indeed he is guilty of the crimes he is accused of, I am gratified that he is in this procedure, involved in a procedure that will bring him to justice.
"I have confidence that the procedure will reveal whether he is guilty or not."
The court was shown an ABC News report in which Farrow told Campbell to "step up" and do her part in the prosecution.
She told the reporter: "I'm eager to see the people of Liberia and Sierra Leone see justice. They need that."
The actress was asked about her "preoccupation" with Africa, and her particular interest in Darfur.
She took part in a water-only fast to call for justice in the region, lasting into a 13th day.
Farrow was asked about her apparent view that Sudanese president Omar al-Bashir is guilty of genocide even though he has not yet been tried.
She said: "My view is that he is guilty."
Mr Anyah showed Farrow a section of her own website on which she posted a link to a Guardian article.
The article was published online last Thursday, when Campbell gave her evidence to the court.
Farrow also copied and pasted an edited version of the article on her blog in which she removed some words.
In reference to Campbell's alleged receipt of diamonds from Taylor, the Guardian article stated: "Prosecutors say the story, if true, would back up allegations that Taylor traded guns to neighbouring Sierra Leone rebels in exchange for uncut diamonds."
In her post, Farrow removed the qualifying words, "if true", so the sentence appeared: "Prosecutors say the story, backs up allegations that Taylor traded guns to neighbouring Sierra Leone rebels in exchange for uncut diamonds."
Farrow said it was a "personal blog" and she could not bring herself to write "if true" because it was her belief that it was true.
But she said: "In retrospect I should have left it in."
Justice Julia Sebutinde asked Farrow if her recollection of a "huge diamond" may have been confused by a similar stone featuring in the film Blood Diamond.
Farrow conceded that Campbell may not have used the word "huge".
She said: "I know she didn't say 'a few' and certainly not 'stones'.
"She may not have used the word 'huge' but she did say a diamond.
"My recollection might not be accurate on the size part."