She refused to answer, claiming spousal privilege, and later successfully sought a Federal Court injunction preventing the commission from asking further questions about Ewan Stoddart's business affairs.
The Crime Commission appealed against the decision in the High Court.
Spousal privilege was a centuries-old common law rule that held that a spouse was incompetent as a witness either for or against his or her partner, lodged in the principle of the unity of a husband and wife and their joint interests.
The rule was coupled with the privilege of self-incrimination, except in cases involving violence by one partner against the other.
The right not to be forced to give evidence against a spouse is upheld in United States federal courts, but in England and Wales communications within a marriage are no longer privileged by common law.
Laws of evidence now provide British spouses the right to testify for or against their partners, but give prosecutors only limited powers to compel one spouse to give evidence against another.
Before the High Court the Crime Commission argued that the privilege did not exist in common law in Australia, and that while British law gave spousal relationships special recognition, it was never possible to exclude evidence simply on the basis that it was a private conversation between a married couple.
"The law of the United Kingdom quite clearly illustrates that spousal privilege is based on statutory enactment and not in the common law," it said.
The argument has been accepted in Queensland, and the Taxation Office this year said the common law privilege against spousal incrimination did not apply to its access and information-gathering powers.
Yesterday the High Court ruled that spousal privilege did not exist in common law, and that Louise Stoddart was a competent witness who should have been compelled to give answers under the Australian Crime Commission Act.
Its ruling said that she had sought to extend her common law privilege beyond self-incrimination to that of incrimination of her spouse by her evidence, supported by the failure of the commission's act to restrict or abrogate the extended privilege.
"In our view, it cannot be said that at the time of the enactment of the act in 2002 the common law in Australia recognised the privilege asserted by Mrs Stoddart or that it does so now," the ruling said.