Erin Patterson's conviction for the deaths by poisoning of her estranged husband's relatives has prompted fevered speculation across Australia about her motive.

The Supreme Court has revealed the jury was accidentally sequestered in the same hotel as a key police witness and two members of the prosecution's team for the majority of the deliberations.

The Australian woman was convicted of murdering three elderly relatives of her estranged husband with a meal laced with poisonous mushrooms, and attempting to murder a fourth, in a case that gripped the country.