What is a 'predatory marriage' and can it be undone after an elderly person has already married?

A "predatory marriage" describes a situation where someone deliberately marries a vulnerable, often elderly or cognitively impaired person, primarily to gain access to their money or property rather than out of a genuine relationship. Because marriage can affect how an estate is ultimately divided — for example, through a surviving spouse's right to claim an equalization payment under the Family Law Act, or a share on intestacy — a predatory marriage can function as a way to redirect an older person's estate away from their existing family.

Yes, it can potentially be undone, though not through an ordinary divorce. Because the concern is usually that the person lacked the legal capacity to marry in the first place, an interested party can bring a court application seeking to have the marriage declared void, based on evidence the person didn't understand the nature of the marriage or its consequences at the time. This is a distinct legal question from testamentary capacity, and it doesn't automatically follow that someone lacking capacity to make a will also lacked capacity to marry, or vice versa. Given how fact-specific and medically involved these cases are, get legal advice as soon as a predatory marriage is suspected, rather than waiting.