Carole White said Mr Taylor, promised during the dinner at Nelson Mandela's residence in 1997 that he would present the gift to Naomi Campbell, who she said was sitting next to him.
She followed actress Mia Farrow in flatly contradicting Campbell's claim - made under oath at the Hague war crimes trial last week - that she did not know who supplied the gems.
Miss Farrow, 65, told the court in The Hague that the British model had told her, and three of her children, that men, representing Mr Taylor, had given her a diamond. They were sent by Charles Taylor and they had given her a huge diamond," she said.
"Naomi Campbell joined us, before she even sat down, she recounted the events of the evening. "Naomi Campbell said they came from Charles Taylor." The award winning American actress said that she had phoned the model last year to plead with her to give evidence against Charles Taylor after the supermodel refused to testify until she was subpoenaed to appear under threat of imprisonment on August 5.
Critical to their case is the allegation that Mr Taylor's staff gave Miss Campbell uncut gems as a present after they met at a star studded gala attended by Miss Farrow, the Nelson Mandela, his future wife Graca Machel, Quincy Jones, Imran and Jemina Khan.
Miss Farrow and Ms White attended the dinner, a charity event to raise money for Mr Mandela's children's charity, with two of her sons and a daughter.
Prosecutors and UN judges pressed Miss Farrow three times on whether the British model had said the diamonds came from the African warlord, something Miss Campbell, 40, repeatedly denied.
"Naomi Campbell entered the room where my children and I were already eating breakfast.
Gerard Butler is rumored to have hooked up with Cassandra Hepburn (2005), Rosario Dawson (2007), Cameron Diaz (2008), Lindsay Lohan (2009), Jessica Biel (2011) and Ashley Greene (2011).
Lizzie Cundy is rumored to be dating Gerard Butler since July 2014.
Scottish actor who has appeared in film and television, Gerard Butler is a son of Margaret Butler and Edward Butler, a bookmaker. Butler has been a supporter of a charity named 'Mary's Meals' since 2010.