De Lille said in her statement that the serious allegations against President Jacob Zuma have not been refuted and he has not answered to them.
De Lille is the first to testify in phase two of the commission after unsuccessful arms bidder Richard Young failed to arrive on Monday.
Phase two is expected to deal with the alleged corruption and fraud and will see various whistle blowers testify.
De Lille first exposed the deal during her time in parliament in 1999. She presented a file on the deal to Parliament – know as the De Lille dossier – that has been submitted as evidence to Judge Willie Seriti.
In De Lille’s six-page statement before the commission she said she first came to know of the irregularities when concerned ANC members approached her.
“I must emphasise the De Lille dossier contains allegations, which I believe the government should investigate,” she said in the statement.
She added that two of those who were alleged to be involved, Schabir Shaid and Tony Yengeni were convicted because of the dossier.
She added that the third person mentioned in her dossier, president Zuma was charged with various ‘serious allegations’.
“Although the charges were withdrawn the serious allegations against Zuma has never been refuted or even answered by him,” she said.
After De Lille has been lead in her evidence in chief it is expected that she will be cross-examined by Lawyers for Human Rights.